量子物理
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显示 2025年08月06日， 星期三 新的列表
- [1] arXiv:2508.02772 [中文pdf, pdf, html, 其他]
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标题： 通过强非马尔可夫耦合下的能量不变催化稳定自旋链量子电池中的激子能标题： Stabilizing ergotropy in Spin-Chain Quantum Batteries via Energy-Invariant Catalysis under Strong Non-Markovian Coupling评论： 9页，5图主题： 量子物理 (quant-ph)
量子电池(QBs)已成为微尺度能量存储的有前途的平台，但大多数现有研究假设系统与环境耦合较弱且遵循马尔可夫动力学。 我们探讨了物理催化如何调节与腔环境强耦合的自旋链量子电池的最大可提取功(熵能)。 我们使用一种纳卡吉马-茨万茨格类型的非马尔可夫主方程对系统进行建模，并在各种物理参数下模拟熵能的时间演化。 我们的结果表明，增加催化剂-自旋耦合、自旋能量或腔频率可以有效抑制熵能振荡并产生准稳态熵能区域，而过于强的催化剂，尤其是在这种情况下系统-环境耦合增加时，可能会破坏功的提取。 这项研究展示了量子催化如何作为控制旋钮，在强耦合的非马尔可夫区域内优化电池性能。
Quantum batteries (QBs) have emerged as promising platforms for microscale energy storage, yet most existing studies assume weak system-environment coupling and Markovian dynamics. Here we explore how physical catalysis can regulate the maximum extractable work (ergotropy) of a spin-chain QB strongly coupled to a cavity environment. We model the system using a Nakajima-Zwanzig-type non-Markovian master equation and simulate the time evolution of ergotropy under various physical parameters. Our results show that increasing the catalyst-spin coupling, spin energy or cavity frequency can effectively suppress ergotropy oscillations and yield quasi-stationary ergotropy regime, while overly strong catalyst, especially when accompanied by increasing system-environment coupling under such conditions, can destabilize work extraction. This study demonstrates how quantum catalysis can serve as a control knob for optimizing battery performance in strongly coupled non-Markovian regimes.
- [2] arXiv:2508.02783 [中文pdf, pdf, html, 其他]
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标题： 通过双速率随机和准周期驱动协议的加热抑制标题： Heating suppression via two-rate random and quasiperiodic drive protocols评论： v1：18页，9图主题： 量子物理 (quant-ph) ; 统计力学 (cond-mat.stat-mech)
我们研究了一维非可积PXP自旋链在磁场中受到随机和准周期驱动的两种不同的驱动协议。这些协议中的每一个都涉及两个驱动频率的方形脉冲，这两个频率是彼此的整数倍。对于第一类协议，脉冲的持续时间通过振幅$dT$随机改变，而对于第二类协议，我们使用随机/准周期的偶极驱动，其中准周期性是通过Thue-Morse（TM）或斐波那契序列实现的。对于这两种协议，我们确定了参数范围，在这些范围内，由于接近由双速率驱动引起的精确动力学冻结，受驱动链的热化被显著减缓。我们还研究了这些受驱动系统略微偏离冻结极限时的性质。对于第一类协议，我们证明了存在一个特殊的$dT$值，此时热化率保持较小，并为这种缓慢的热化提供了分析解释。与之前研究的涉及单个频率的随机/准周期驱动不同，对于第二类协议，我们发现TM准周期驱动导致的热化比那些周期性或遵循随机或准周期斐波那契序列的驱动协议要明显缓慢。我们通过小系统尺寸的精确计算或在大驱动振幅极限下的微扰分析，对这些现象提供了定性的半解析理解。我们的分析揭示了这类双频率协议在减少受驱动量子系统加热中的核心作用。我们讨论了可以测试我们理论的实验。
We study a random and quasiperiodically driven one-dimensional non-integrable PXP spin chain in a magnetic field for two distinct drive protocols. Each of these protocols involves square pulses with two driving frequencies which are integer multiples of each other. For the first class of protocols, the duration of the pulse is changed randomly by an amplitude $dT$ while for the second class we use a random/quasiperiodic dipolar drive, where the quasiperiodicity is implemented using the Thue-Morse (TM) or Fibonacci sequences. For both protocols, we identify parameter regimes for which the thermalization of the driven chain is drastically slowed down due to proximity to a two-rate drive induced exact dynamical freezing. We also study the properties of these driven system moving slightly away from the freezing limit. For the first type of protocols, we show the existence of special value of $dT$ for which the thermalization rate remains small and provide an analytic explanation for such slow thermalization. For the second class of protocols, in contrast to random/quasiperiodic drives involving a single frequency studied earlier, we find that the TM quasiperiodic drive leads to a distinctly slower thermalization than that for drive protocols which are either periodic or follow a random or quasiperiodic Fibonacci sequence. We provide a qualitative semi-analytic understanding of these phenomena either using an exact calculation for small system sizes or carrying out a perturbative analysis in the large drive-amplitude limit. Our analysis brings out the central role of such two-frequency protocols in the reduction of heating in driven quantum systems. We discuss experiments which can test our theory.
- [3] arXiv:2508.02788 [中文pdf, pdf, html, 其他]
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标题： 共形场理论中的测量诱导纠缠标题： Measurement-Induced Entanglement in Conformal Field Theory评论： 4.5 + 13页主题： 量子物理 (quant-ph) ; 统计力学 (cond-mat.stat-mech) ; 强关联电子 (cond-mat.str-el) ; 高能物理 - 理论 (hep-th)
局部测量可以彻底改变多体纠缠的模式，尤其是在长程纠缠的量子临界态中。 然而，针对测量对多体态影响的解析结果仍然很少，测量通常被近似为强制特定的测量结果。 我们研究了汤川-卢廷液态中的测量诱导纠缠（MIE），这是一个由低能下紧致自由玻色共形场理论（CFT）描述的1+1维量子临界态的广泛家族。 通过测量局部电荷算符，我们表明MIE是完全普遍的、共形不变的，并且取决于CFT的算符内容。 使用复制技巧来处理测量结果的随机性，我们精确计算了汤川-卢廷液态中的MIE，与矩阵乘积态计算结果非常吻合。 我们表明，物理量子测量的MIE与强制测量结果引起的纠缠本质上不同，并且在共形不变边界条件上的玻恩平均中有自然的解释。
Local measurements can radically reshape patterns of many-body entanglement, especially in long-range entangled quantum-critical states. Yet, analytical results addressing the effects of measurements on many-body states remain scarce, and measurements are often approximated as forcing specific measurement outcomes. We study measurement-induced entanglement (MIE) in Tomonaga-Luttinger liquids, a broad family of 1+1d quantum critical states described at low energies by compact free boson conformal field theories (CFT). Measuring the local charge operator, we show that the MIE is entirely universal, conformally invariant, and depends on the operator content of the CFT. Using a replica-trick to address the randomness of the measurement outcomes, we compute the MIE exactly for Tomonaga-Luttinger liquids, in very good agreement with matrix-product state calculations. We show that the MIE for physical quantum measurements is fundamentally different from the entanglement induced by forcing measurement outcomes, and has a natural interpretation in terms of Born averaging over conformally-invariant boundary conditions.
- [4] arXiv:2508.02793 [中文pdf, pdf, html, 其他]
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标题： 稀释弱局域金属中接近金属-绝缘体转变的强电子-电子相互作用标题： Strong electron-electron interactions in a dilute weakly-localized metal near a metal-to-insulator transitionNicolò D'Anna, Jamie Bragg, Aidan G. McConnell, Procopios C. Constantinou, Juerong Li, Taylor J.Z. Stock, Steven R. Schofield, Neil J. Curson, Y. Soh, Marek Bartkowiak, Simon Gerber, Markus Müller, Guy Matmon, Gabriel Aeppli评论： 9页，4图主题： 量子物理 (quant-ph) ; 强关联电子 (cond-mat.str-el)
由于通过化学掺杂或电场栅控很容易从绝缘体转变为金属，硅是现代信息技术的核心，并且仍然是量子计算的候选平台。 这种材料的金属-绝缘体转变因此成为凝聚态物理中最被研究的现象之一，每当引入一种新的制造技术时，都会从中获得相当大的收益。 在这里，我们利用了最近在创建类似玻尔原子的掺杂层方面的进展，实现了在半填充情况下二维无序 Hubbard 模型及其金属-绝缘体转变（MIT）作为原子间平均距离的函数。 我们使用气相掺杂前驱分子在硅上进行掺杂，以创建厚度仅为 0.4~nm 且稀释度高达 10$^{13}$~cm$^{-2}$的砷和磷$\delta$-层。 在接近绝缘态时，常规的弱局域化效应在高掺杂浓度下普遍存在，这是由于平面内电子的轨道运动引起的，现在则被电子-电子相互作用贡献所主导，这些贡献遵循顺磁 Zeeman 标度定律。 后者对电导率有负贡献，因此不能用靠近 MIT 的涌现 Kondo 区域来解释。
Because it is easily switched from insulator to metal either via chemical doping or electrical gating, silicon is at the core of modern information technology and remains a candidate platform for quantum computing. The metal-to-insulator transition in this material has therefore been one of the most studied phenomena in condensed matter physics, and has been revisited with considerable profit each time a new fabrication technology has been introduced. Here we take advantage of recent advances in creating ultra-thin layers of Bohr-atom-like dopants to realize the two-dimensional disordered Hubbard model at half-filling and its metal-to-insulator transition (MIT) as a function of mean distance between atoms. We use gas-phase dosing of dopant precursor molecules on silicon to create arsenic and phosphorus $\delta$-layers as thin as 0.4~nm and as dilute as 10$^{13}$~cm$^{-2}$. On approaching the insulating state, the conventional weak localization effects, prevalent at high dopant densities and due to orbital motion of the electrons in the plane, become dominated by electron-electron interaction contributions which obey a paramagnetic Zeeman scaling law. The latter make a negative contribution to the conductance, and thus cannot be interpreted in terms of an emergent Kondo regime near the MIT.
- [5] arXiv:2508.02815 [中文pdf, pdf, html, 其他]
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标题： 调整原子阵列中的相互作用范围标题： Tailoring interaction ranges in atom arrays评论： 六位数主题： 量子物理 (quant-ph)
我们介绍了一种方法，通过有效修改电磁真空的模式，利用远失谐中继原子来合成工程化光镊原子阵列中的偶极相互作用范围。 我们在绝热消除中继原子后推导了感兴趣原子的运动方程。 我们展示了该方案在现实实验参数范围内的有效性，针对圆状和低角动量里德伯原子态。
We introduce a method to synthetically engineer the range of dipolar interactions in tweezer atom arrays by effectively modifying the modes of the electromagnetic vacuum with far-detuned relay atoms. We derive equations of motion for the atoms of interest after adiabatic elimination of the relay atoms. We show the effectiveness of the scheme for realistic experimental parameter regimes with circular and low-angular-momentum Rydberg atom states.
- [6] arXiv:2508.02822 [中文pdf, pdf, html, 其他]
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标题： 量子算法用于线性矩阵方程标题： Quantum algorithm for linear matrix equations评论： 24页，1图主题： 量子物理 (quant-ph)
我们描述了一种高效的量子算法，用于求解线性矩阵方程 AX+XB=C，其中 A、B 和 C 是给定的复数矩阵，X 是未知数。 这被称为西尔维斯特方程，在控制理论和物理学中有着基础应用。 与以往量子线性代数求解器将解编码为量子态的方式不同，我们的方法通过某种缩放因子构建解矩阵 X 的块编码。 这使我们能够以比从准备 X 作为量子态更快的速度获得 X 的元素的某些属性。 实现此块编码的量子电路的查询和门复杂度几乎与依赖于 A 和 B 的条件数成线性关系，并与维度和误差倒数的对数成比例。 我们展示了如何让量子电路高效地解决 BQP 完全问题，讨论了我们方法的潜在应用和扩展，它与里卡蒂方程的联系，并对开放问题进行了评论。
We describe an efficient quantum algorithm for solving the linear matrix equation AX+XB=C, where A, B and C are given complex matrices and X is unknown. This is known as the Sylvester equation, a fundamental equation with applications in control theory and physics. Rather than encoding the solution in a quantum state in a fashion analogous to prior quantum linear algebra solvers, our approach constructs the solution matrix X in a block-encoding, rescaled by some factor. This allows us to obtain certain properties of the entries of X exponentially faster than would be possible from preparing X as a quantum state. The query and gate complexities of the quantum circuit that implements this block-encoding are almost linear in a condition number that depends on A and B, and depend logarithmically in the dimension and inverse error. We show how our quantum circuits can solve BQP-complete problems efficiently, discuss potential applications and extensions of our approach, its connection to Riccati equation, and comment on open problems.
- [7] arXiv:2508.02855 [中文pdf, pdf, html, 其他]
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标题： 一种资源高效的量子行走者量子RAM标题： A resource-efficient quantum-walker Quantum RAM评论： 5+15页，7图主题： 量子物理 (quant-ph)
高效且连贯的数据检索和存储对于利用量子算法的速度优势是至关重要的。 这种基本任务由量子随机存取存储器（qRAM）来解决。 尽管它们具有良好的扩展性，但当前的qRAM方案需要过多的资源，并依赖于超出当前硬件能力的操作，这使得其实现效率低下。 我们引入了一种新架构，在保持量子查询最优复杂度扩展性的同时显著减少了资源需求。 此外，与之前的方案不同，我们的算法设计仅基于局部单位操作和有限数量的量子行走者在单一二叉树上的短程相互作用的简单重复操作模块。 这种新方法不仅通过减少必要操作的复杂性简化了实验要求，还通过确保资源高效的模块化设计提高了架构的可扩展性，同时保持了最优的量子查询性能。
Efficient and coherent data retrieval and storage are essential for harnessing quantum algorithms' speedup. Such a fundamental task is addressed by a quantum Random Access Memory (qRAM). Despite their promising scaling properties, current qRAM proposals demand excessive resources and rely on operations beyond the capabilities of current hardware requirements, rendering their practical realization inefficient. We introduce a novel architecture that significantly reduces resource requirements while preserving optimal complexity scaling for quantum queries. Moreover, unlike previous proposals, our algorithm design leverages a simple, repeated operational block based exclusively on local unitary operations and short-range interactions between a limited number of quantum walkers traveling over a single binary tree. This novel approach not only simplifies experimental requirements by reducing the complexity of necessary operations but also enhances the architecture's scalability by ensuring a resource-efficient, modular design that maintains optimal quantum query performance.
- [8] arXiv:2508.02902 [中文pdf, pdf, html, 其他]
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标题： 超快速绝热量子门的脉冲整形标题： Pulse Shaping for Ultra-Fast Adiabatic Quantum Gates主题： 量子物理 (quant-ph)
量子计算中的一个基本挑战是增加量子比特相干时间内的操作数量。 虽然可以通过缩短门操作时间来实现这一点，但使用更短的信号会增加其带宽，并可能导致泄漏到能量上分离的状态。 抑制短脉冲泄漏的常用方法是通过绝热门的导数去除（DRAG）方法，然而，该方法依赖于射频（RF）信号的IQ调制，因此不能应用于基带信号，例如用于半导体自旋量子比特的情况。 本文提出了一种新技术，延迟泄漏减少（DLR），通过使用控制信号的时间延迟重复，在基带控制下也能抑制特定频率的泄漏，从而实现快速、高保真度的操作。 我们将DLR应用于两个自旋量子比特之间的绝热CZ门，并在共振频率差仅为100 MHz的情况下，在9.4 ns内实现了超过99.9%的保真度。 为了实现所提出的控制方法的实验实现，我们还评估了生成控制脉冲的电子硬件的采样率对保真度的影响，从而设定了任何实验演示的最低硬件要求。
A fundamental challenge in quantum computing is to increase the number of operations within the qubit coherence time. While this can be achieved by decreasing the gate duration, the use of shorter signals increases their bandwidth and can cause leakage into energetically separated states. A common method to suppress leakage for short pulses is the Derivative Removal by Adiabatic Gate (DRAG) method, which however, relies on IQ modulation of radio-frequency (RF) signals, thus cannot be applied to the baseband signals, e.g., for semiconductor spin qubits. This paper proposes a novel technique, Delayed Leakage Reduction (DLR), that suppresses leakage at targeted frequencies even for baseband control by using time-delayed repetitions of the control signal to enable rapid, high-fidelity operations. We apply DLR on the adiabatic CZ gate between two spin qubits and achieve fidelities exceeding 99.9% within 9.4 ns for a resonance frequency difference of only 100 MHz. Towards the experimental realization of the proposed control method, we also assess the impact on the fidelity of the sampling rate of the electronic hardware generating the control pulse, thus setting the minimum hardware requirements for any experimental demonstration.
- [9] arXiv:2508.02915 [中文pdf, pdf, html, 其他]
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标题： 在IBM量子计算机上的中温拓扑Uhlmann相标题： Intermediate-temperature topological Uhlmann phase on IBM quantum computers评论： 13页，6图，3表主题： 量子物理 (quant-ph) ; 其他凝聚态物理 (cond-mat.other)
自旋-1系统可以在中间温度下表现出一个拓扑区间，其中包含由拓扑平凡的低温和高温区间夹着的量化乌尔曼相位。 我们提出了一种量子电路，包括系统量子比特和辅助量子比特以及一个探测量子比特，该电路制备了对应于有限温度下自旋-1系统的纯化态的初始状态，根据乌尔曼过程演化系统，并通过探测量子比特的期望值测量乌尔曼相位。 尽管经典模拟表明量化乌尔曼相位可以在IBM的噪声中等规模量子（NISQ）计算机上观测到，但未经任何优化的电路实现会超出误差预算的门数，导致信号无法解析。 通过一系列使用Qiskit和BQSQit的优化，门数可以显著减少，使乌尔曼相位的跳跃更加明显。 IBM量子计算机最近的硬件升级进一步改善了信号，并在NISQ硬件上更清晰地展示了有趣的有限温度拓扑现象。
A spin-1 system can exhibit an intermediate-temperature topological regime with a quantized Uhlmann phase sandwiched by topologically trivial low- and high-temperature regimes. We present a quantum circuit consisting of system and ancilla qubits plus a probe qubit which prepares an initial state corresponding to the purified state of a spin-1 system at finite temperature, evolves the system according to the Uhlmann process, and measures the Uhlmann phase via expectation values of the probe qubit. Although classical simulations suggest the quantized Uhlmann phase is observable on IBM's noisy intermediate-scale quantum (NISQ) computers, an implementation of the circuit without any optimization exceeds the gate count for the error budget and results in unresolved signals. Through a series of optimization with Qiskit and BQSQit, the gate count can be substantially reduced, making the jumps of the Uhlmann phase more visible. A recent hardware upgrade of IBM quantum computers further improves the signals and leads to a clearer demonstration of interesting finite-temperature topological phenomena on NISQ hardware.
- [10] arXiv:2508.02946 [中文pdf, pdf, html, 其他]
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标题： 电耦合腔-磁系统中普尔塞效应的观察标题： Observation of Purcell Effect in Electrically Coupled Cavity-Magnet System主题： 量子物理 (quant-ph) ; 中尺度与纳米尺度物理 (cond-mat.mes-hall)
我们报告了在腔体-金属磁体混合系统中通过电场介导耦合观察到的普尔塞效应。 在此配置中，微米线中的微波感应轴向电流产生环形磁场，驱动磁化微米线的铁磁共振（FMR）。 场依赖性透射和反射光谱揭示了与普尔塞区域一致的腔体扰动，在该区域中磁损耗率超过光-物质耦合强度。 尽管磁体积较小（$\sim 10^{-13}\,\text{m}^3$），但在室温和7 mK下进行的测量显示耦合速率高达56 MHz，比传统耦合在磁反相点处预期的值高一个数量级。 时域衰减测量直接显示了腔体光子寿命的磁场所致修改，与理论预测一致。 这些结果建立了一种通过几何和电场介导相互作用将微波场耦合到金属磁体的通用方法，为混合腔体-磁体系统开辟了新的机会。
We report the observation of the Purcell effect in a cavity-metallic magnet hybrid system using electric-field-mediated coupling. In this configuration, microwave-induced axial currents in the microwire induce circular magnetic fields that drive the ferromagnetic resonance (FMR) of the magnetized microwire. Field-dependent transmission and reflection spectroscopies reveal a clear cavity perturbation consistent with the Purcell regime, in which the magnetic loss rate exceeds the light-matter coupling strength. Despite the small magnetic volume ($\sim 10^{-13}\,\text{m}^3$), measurements performed at both room temperature and 7 mK show coupling rates as high as 56 MHz, one order of magnitude stronger than expected from conventional coupling at the magnetic antinode. Time-domain ringdown measurements directly show the magnetic-field-dependent modification of the cavity photon lifetime, in agreement with theoretical predictions. These results establish a versatile approach for coupling microwave fields to metallic magnets via geometric and electric-field-mediated interactions, opening new opportunities for hybrid cavity-magnet systems.
- [11] arXiv:2508.03052 [中文pdf, pdf, html, 其他]
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标题： 今天的实验足以验证引力的量子本质标题： Today's Experiments Suffice to Verify the Quantum Essence of Gravity主题： 量子物理 (quant-ph) ; 广义相对论与量子宇宙学 (gr-qc)
利用引力介导的纠缠实验，运用量子信息的概念来论证，如果引力相互作用在两个系统之间产生纠缠，那么引力不能由经典系统来描述。 然而，所提出的实验仍超出我们当前的技术能力，乐观的预测认为该实验将在短期内无法实现。 在这里，我们利用量子信息技术来论证，目前的物质波干涉仪已经足以间接证明引力相互作用在两个系统之间产生纠缠。 具体而言，我们证明了如果在实验中验证了与外部质量发生引力相互作用的单个非定域系统中的薛定谔方程，那么两个非定域系统的时演化将导致引力介导的纠缠。 我们的研究结果表明，对引力量子本质的实验验证即将实现。
The gravity-mediated entanglement experiments employ concepts from quantum information to argue that if gravitational interaction creates entanglement between two systems, then gravity cannot be described by a classical system. However, the proposed experiments remain beyond out current technological capability, with optimistic projections placing the experiment outside of short-term future. Here we leverage quantum information techniques to argue that current matter-wave interferometers are sufficient to indirectly prove that gravitational interaction creates entanglement between two systems. Specifically, we prove that if we experimentally verify the Schr\"{o}dinger equation for a single delocalized system interacting gravitationally with an external mass, then the time evolution of two delocalized systems will lead to gravity-mediated entanglement. Our findings indicate that the experimental verification of the quantum essence of gravity is on the horizon.
- [12] arXiv:2508.03169 [中文pdf, pdf, html, 其他]
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标题： 量子动力学和信息度量在PT对称和反PT对称系统中标题： Quantum Dynamics and Information Measures in PT and Anti-PT-Symmetric Systems评论： 18页，7图主题： 量子物理 (quant-ph)
在本研究中，我们研究在PT和反PT对称非厄米哈密顿下的量子比特动力学，重点研究相位演化、退相干、量子速度极限（QSL）和Rényi纠缠熵。 使用相似变换和Dyson映射，我们分析了在玻色环境中约化密度矩阵的演化。 反PT对称系统表现出更强的抗退相干能力，与PT对称对应物相比，其熵增长更慢，相干时间更长。 QSL行为是非单调的，反映了初始快速演化后逐渐减少的情况。 高阶 Rényi熵显示，反PT对称量子比特更能有效地保持量子信息，为记忆和密码应用提供了优势。
In this study, we investigate qubit dynamics under PT and Anti-PT-symmetric non-Hermitian Hamiltonians, focusing on phase evolution, decoherence, quantum speed limits (QSL), and R\'enyi entanglement entropies. Using similarity transformations and Dyson maps, we analyze the reduced density matrix evolution in bosonic environments. Anti-PT-symmetric systems show enhanced robustness against decoherence, with slower entropy growth and longer coherence times compared to PT-symmetric counterparts. QSL behavior is non-monotonic, reflecting rapid initial evolution followed by a gradual decrease. Higher-order R\'enyi entropies reveal that Anti-PT-symmetric qubits preserve quantum information more effectively, offering advantages for memory and cryptographic applications.
- [13] arXiv:2508.03188 [中文pdf, pdf, html, 其他]
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标题： 探测强驱动和强耦合的超导量子比特-谐振器系统标题： Probing strongly driven and strongly coupled superconducting qubit-resonator systemOleh V. Ivakhnenko, Christoforus Dimas Satrya, Yu-Cheng Chang, Rishabh Upadhyay, Joonas T. Peltonen, Sergey N. Shevchenko, Franco Nori, Jukka P. Pekola评论： 12页，9图主题： 量子物理 (quant-ph)
我们研究了一个强驱动的量子比特，该量子比特与一个量子谐振器强烈连接。 测量的系统是一个超导通量量子比特，与共面波导谐振器耦合，该谐振器与探测馈线弱耦合。 这个混合的量子比特-谐振器系统通过磁通量驱动，并通过馈线用弱探测信号进行探测。 我们观察并理论描述了量子干涉效应，这与通常的单量子比特Landau-Zener-Stückelberg-Majorana干涉不同，因为强耦合扭曲了量子比特的能量水平。
We investigated a strongly driven qubit strongly connected to a quantum resonator. The measured system was a superconducting flux qubit coupled to a coplanar-waveguide resonator which is weakly coupled to a probing feedline. This hybrid qubit-resonator system was driven by a magnetic flux and probed with a weak probe signal through the feedline. We observed and theoretically described the quantum interference effects, deviating from the usual single-qubit Landau-Zener-St\"{u}ckelberg-Majorana interferometry, because the strong coupling distorts the qubit energy levels.
- [14] arXiv:2508.03192 [中文pdf, pdf, 其他]
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标题： 费米子适应的阴影测度用于动态关联函数标题： Fermionic-Adapted Shadow Tomography for dynamical correlation functions主题： 量子物理 (quant-ph) ; 计算物理 (physics.comp-ph)
动力关联函数对于表征量子多体系统对外部扰动的响应是至关重要的。 由于在一般情况下它们的计算在经典上是难以处理的，因此量子算法在这方面很有前景，但大多数依赖于逐个评估单个体可观测量对的暴力测量策略。 在本工作中，我们引入了费米子适应的影子层析技术（FAST）协议，这是一种用于高效计算多个动力关联函数的新框架。 其核心思想是将这些函数重新表述为与影子层析技术兼容的形式。 我们协议中的电路最多需要两次复制测量，并且不需要控制哈密顿量模拟。 我们表明，所提出的协议在各种场景下，相对于量子比特数量，提高了样本效率并减少了测量电路的数量一个或两个数量级。
Dynamical correlation functions are essential for characterizing the response of the quantum many-body systems to the external perturbation. As their calculation is classically intractible in general, quantum algorithms are promising in this aspect, but most rely on brute force measurement strategies that evaluate one body observable pair per circuit. In this work, we introduce Fermionic-Adapted Shadow Tomography (FAST) protocols, a new framework for the efficient calculation of multiple dynamical correlation functions. The key idea is to reformulate these functions into forms that are compatible with shadow tomography techniques. The circuits in our protocols require at most two-copy measurements with uncontrolled Hamiltonian simulation. We show that the proposed protocols enhance sample efficiency and reduce the number of measurement circuits by an order of one or two with respect to the number of qubits across a range of scenarios.
- [15] arXiv:2508.03193 [中文pdf, pdf, html, 其他]
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标题： 预热开放量子系统中的相干热量交换标题： Coherent heat exchange in a prethermalizing open quantum system主题： 量子物理 (quant-ph)
我们通过量子随机热力学的框架，研究了一个简单的模型，该模型表现出一种预热相，即在完全热化之前出现的亚稳态。我们探讨了系统初始状态的能量本征基中量子相干性对与热库进行热量交换过程的影响，以及它们通过热量交换涨落定理所量化的熵产生贡献。这种关系是通过端点测量（EPM）方案推导出来的，这是一种协议，能够考虑非平衡过程中产生的能量交换统计中的初始量子相干性。我们将这些结果与广泛使用的两点测量（TPM）方案的结果进行比较，该方案在构造上无法捕捉到这些量子效应。
We investigate a simple model exhibiting a prethermal phase, i.e. a metastable state that emerges before full thermalization, through the framework of quantum stochastic thermodynamics. We explore the effects of quantum coherence in the energy eigenbasis of the initial state of the system on the process of heat exchange with a bath, and their contribution to entropy production as quantified by a heat-exchange fluctuation theorem. Such relation is derived using the End-Point Measurement (EPM) scheme, a protocol that accounts for initial quantum coherence in the statistics of energy exchanges resulting from a non-equilibrium process. We compare these results with those obtained from the widely used Two-Point Measurement (TPM) scheme which, by construction, fails to capture such quantum effects.
- [16] arXiv:2508.03203 [中文pdf, pdf, html, 其他]
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标题： 量子电路中逻辑深度的热力学特征标题： Thermodynamic Signature of Logical Depth in Quantum Circuits主题： 量子物理 (quant-ph) ; 计算复杂性 (cs.CC)
我们证明，在逐步退相干下，量子电路的内部逻辑结构可以留下明显的热力学特征。 通过将深度、条件分支电路与浅层、均匀电路进行比较——同时控制整体停止概率和物理资源——我们表明，分支架构会引发更多的熵流进入环境。 这种效应由一个逻辑深度因子$L_d$来描述，该因子量化了环境相互作用期间的熵积累。 我们通过详细分析两个4分支量子电路验证了我们的框架，展示了在条件架构与均匀架构之间，$L_d \approx 1.615$的熵产生更大。 一种基于辅助比特的实验协议，使用受控相位门，为在当前量子平台上检测这些热力学特征提供了一条具体的路径。 我们的结果确立了逻辑深度作为一个具有电路设计、编译策略和验证协议意义的物理可测量量。
We demonstrate that the internal logical structure of a quantum circuit can leave a distinct thermodynamic signature under progressive decoherence. By comparing deep, conditionally branching circuits with shallow, uniform counterparts-while controlling for overall halting probability and physical resources-we show that branching architectures induce greater entropy flow into the environment. This effect is captured by a logical depth factor $L_d$, which quantifies entropy accumulation during environmental interactions. We validate our framework through detailed analysis of two 4-branch quantum circuits, demonstrating greater entropy production with $L_d \approx 1.615$ for conditional versus uniform architectures. An ancilla-based experimental protocol using controlled-phase gates provides a concrete pathway for detecting these thermodynamic signatures on current quantum platforms. Our results establish logical depth as a physically measurable quantity with implications for circuit design, compilation strategies, and verification protocols.
- [17] arXiv:2508.03237 [中文pdf, pdf, html, 其他]
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标题： 一种具有纳特斯拉灵敏度的全集成金刚石氮空位磁强计标题： A Fully-integrated Diamond Nitrogen-Vacancy Magnetometer with Nanotesla SensitivityYulin Dai, Wenhui Tian, Qing liu, Bao Chen, Yushan Liu, Qidi Hu, Zheng Ma, Yunpeng Zhai, Haodong Wang, Ying Dong, Nanyang Xu评论： 7页，5图期刊参考： 先进量子技术 2025主题： 量子物理 (quant-ph)
集成钻石氮空位（DNV）中心已成为一种有前景的平台，用于精确的地磁场矢量磁感应，特别是在需要高移动性的应用中。 然而，将所有控制功能集成到紧凑的外形中已被证明具有挑战性，迄今为止限制了移动式DNV磁强计的灵敏度至微特斯拉（uT）级别。 本研究介绍了一种完全集成的DNV磁强计，涵盖了传统平台中通常包含的所有关键组件，同时保持约13厘米*26厘米的紧凑尺寸。 与之前的努力不同，我们通过集成高功率激光器、锁相放大器和数字调制微波源成功解决了这些挑战。 这些自制组件在我们的条件下表现出与商用设备相当的性能，从而实现了2.14 nT/sqrt{赫兹}的最佳灵敏度。 讨论了该系统中的局限性以及可能的未来改进。 这项工作为DNV磁强计在成本效益高、移动式的无人机中的应用铺平了道路，促进了广泛的实际应用。
Ensemble diamond nitrogen-vacancy (DNV) centers have emerged as a promising platform for precise earth-field vector magnetic sensing, particularly in applications that require high mobility. Nevertheless, integrating all control utilities into a compact form has proven challenging, thus far limiting the sensitivity of mobile DNV magnetometers to the uT-level. This study introduces a fully integrated DNV magnetometer that encompasses all the essential components typically found in traditional platforms, while maintaining compact dimensions of approximately 13 cm * 26 cm. In contrast to previous efforts, we successfully address these challenges by integrating a high-power laser, a lock-in amplifier, and a digitally-modulated microwave source. These home-made components show comparable performance with commercial devices under our circumstance, resulting in an optimal sensitivity of 2.14 nT/sqrt{Hz}. The limitations in this system as well as possible future improvements are discussed. This work paves the way for the use of DNV magnetometry in cost-effective, mobile unmanned aerial vehicles, facilitating a wide range of practical applications.
- [18] arXiv:2508.03261 [中文pdf, pdf, html, 其他]
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标题： 具有不完美地址错误的噪声量子计算表征标题： Characterizing noisy quantum computation with imperfectly addressed errors主题： 量子物理 (quant-ph)
量子协议在硬件上受到噪声的影响，这会妨碍其性能。 用于解决错误的协议，如错误校正或错误缓解，如果噪声违反了这些协议有效的关键假设，可能无法对抗量子计算中的错误。 然而，用于表征现实运行条件下此类失败的工具是有限的。 例如，虽然可以使用暴力模拟来表征这些失败对少量输入状态的影响，但这些模拟缺乏对噪声如何在完整的量子希尔伯特空间中转换状态空间的完整描述。 在本工作中，我们将受现实噪声影响的量子计算与一组随机超算子的集合相关联，并研究该集合上的特征值和奇异谱分布。 我们提出了一种新的理论框架，利用矩阵切尔诺夫集中不等式来表征随机复矩阵的奇异值。 使用我们的框架，我们分析了错误缓解和错误校正中不完全解决的错误。 我们发现奇异谱分布取决于噪声如何违反这些协议的关键假设。 最后，我们定量讨论了我们的工作如何应用于理解量子计算的极限行为，例如为特定家族的量子马尔可夫过程建立谱隙和弛豫时间。 我们的工作为诊断何时应信任噪声量子计算机的输出提供了新工具的道路。
Quantum protocols on hardware are subject to noise that prohibits performance. Protocols for addressing errors, such as error correction or error mitigation, may fail to combat errors in quantum computation if noise violates critical assumptions required for these protocols to be effective. However, tools for characterizing such failures in realistic operating conditions are limited. For example, while brute force simulations may be used to characterize the impact of such failures on a handful of input states, such simulations lack a complete description for how noise transforms state-spaces in the full quantum Hilbert space. In this work, we associate quantum computation subject to realistic noise to an ensemble of random superoperators and study the eigen- and singular spectral distributions over this ensemble. We propose a new theoretical framework to characterize singular values of random complex matrices using matrix Chernoff concentration. Using our framework, we analyze imperfectly addressed errors in error mitigation and error correction. We find that distributions of singular spectra depend on how noise violates critical assumptions of these protocols. Finally, we quantitatively discuss how our work may be applied to understanding limiting behavior of quantum computation, such as establishing spectral gaps and relaxation times for specific families of quantum Markov processes. Our work paves the way for new tools to diagnose when to trust the output of noisy quantum computers.
- [19] arXiv:2508.03295 [中文pdf, pdf, html, 其他]
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标题： 频域子空间编码用于多路复用量子秘密共享标题： Frequency subspace encoding for multiplexed quantum secret sharing主题： 量子物理 (quant-ph)
量子秘密共享（QSS）是一种多方量子通信协议，可以通过双粒子纠缠和相对相位编码来实现。 以往的实现通常在泵浦中编码相位，并在整个源带宽上应用，从而通过波长复用限制了可扩展性。 相比之下，我们提出了一种标准QSS协议的变体，利用频率相关性通过一个源连接多个用户。 拥有源访问权限的秘密所有者通过对接收到的宽带偏振纠缠光子对应用频率依赖的相位调制来编码经典信息。 因此，每个频率信道在秘密所有者和一对用户之间提供一个独立的QSS会话。 我们展示了200 GHz ITU网格中的信道对至少90%的状态保真度，使用足够密集的波长分复用滤波器可以扩展到超过40个频率信道。 我们的结果为在波长复用网络上实现多用户秘密共享提供了一条资源高效的路径，消除了对多个双光子或多光子源的需求。
Quantum secret sharing (QSS) is a multi-party quantum communication protocol that can be realized with bipartite entanglement and relative phase encoding. Previous implementations typically encoded the phase in the pump, applying it across the entire source bandwidth, thereby limiting scalability via wavelength multiplexing. In contrast, we present a variant of the standard QSS protocol that leverages frequency correlations to connect multiple users with a single source. The secret owner, who has access to the source, encodes classical information by applying frequency-dependent phase modulation to a broadband polarization-entangled photon pair. Each frequency channel therefore provides an independent QSS session among the secret owner and a pair of users. We demonstrate state fidelities of at least 90% for a channel pair of the 200 GHz ITU grid, which could be extended to more than 40 frequency bins with adequate dense-wavelength division multiplexed filters. Our results provide a resource-efficient path toward multi-user secret sharing over wavelength-multiplexed networks, eliminating the need for multiple two-photon or multi-photon sources.
- [20] arXiv:2508.03303 [中文pdf, pdf, html, 其他]
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标题： 两色连续变量纠缠光的相位相干控制标题： Coherent phase control of two-color continuous variable entangled light评论： 8页，6图主题： 量子物理 (quant-ph) ; 光学 (physics.optics)
连续变量爱因斯坦-波多尔斯基-罗森（EPR）态是安全量子通信和分布式量子传感的资源。 在这里，我们提出一种技术，用于对由频率非简并光学参量振荡器生成的双色EPR态进行相干控制。 该方案允许对由200纳米分离的两个EPR量子场的同相检测进行鲁棒控制。 我们将我们的控制方案应用于稳定和表征一种显示声学频率范围内9分贝双模压缩的双色光强纠缠态，使其成为量子网络和量子计量学的有价值工具。
A continuous variable Einstein-Podolsky-Rosen (EPR) state is a resource for secure quantum communication and distributed quantum sensing. Here we present a technique for coherent control of the two-color EPR state generated by a frequency nondegenerate optical parametric oscillator. The scheme allows for robust control of the homodyne detection of each of the two EPR quantum fields separated by 200 nanometers. We apply our control scheme to stabilize and characterize a strong entangled state of two-color light displaying 9 dB of two-mode squeezing in the acoustic frequency range, making it a valuable tool for quantum networking and quantum metrology.
- [21] arXiv:2508.03367 [中文pdf, pdf, html, 其他]
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标题： 探测器相关性和相干态假说的零检验标题： Detector Correlations and Null Tests of the Coherent State Hypothesis评论： 11页，0图，对威尔茨克量子中心研讨会关于高能粒子量子纠缠的贡献，将发表在《国际现代物理杂志A》特刊上主题： 量子物理 (quant-ph) ; 广义相对论与量子宇宙学 (gr-qc)
我们讨论两个共振探测器之间相关性的统计特性。 我们表明，这允许简单的零检验来验证相干态假设，不受真空（量子）噪声的影响。 辐射场的互补特性，{\it 例如}，在数目或相位上的压缩，可以通过适当的探测策略来揭示。
We discuss the statistics of correlations between two resonant detectors. We show that this allows simple null tests of the coherent state hypothesis, free of vacuum (quantum) noise. Complementary aspects of the radiation field, {\it e.g.}, squeezing in number or phase, can be revealed through appropriate detection strategies.
- [22] arXiv:2508.03376 [中文pdf, pdf, html, 其他]
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标题： 通过电路编织和架构搜索的高效变分量子算法标题： Efficient Variational Quantum Algorithms via Circuit Knitting and Architecture Search评论： 13页，10图主题： 量子物理 (quant-ph) ; 新兴技术 (cs.ET)
当前的量子硬件在可用量子位的数量上相较于实际量子算法的要求存在显著限制。 通过将较大的量子电路分割成较小的部分，这些部分可以由当前设备执行，电路编织已被提出作为解决此问题的方法。 然而，这种方法通常会导致较高的采样开销，该开销随着切割点数量的增加呈指数增长。 在本文中，我们引入了CKVQA，这是一个将电路编织应用于变分量子算法（VQAs）的框架。 通过采用适应此场景的量子电路架构搜索，CKVQA旨在通过识别在算法性能和采样开销之间达到良好平衡的参数化量子电路来最小化采样开销。 此外，由于电路编织生成多个子电路，我们开发了一种子电路级别的优化方法，以加速VQAs的训练并减少整体执行时间。 我们将该框架应用于两种广泛使用的VQAs：量子近似优化算法和变分量子本征求解器。 我们的数值结果表明，CKVQA框架显著减少了采样开销，同时保持与传统参数化量子电路设计相当的准确性。
Current quantum hardware presents a significant limitation in the number of available qubits compared to the requirements of practical quantum algorithms. Circuit knitting has been proposed as a solution to this issue by partitioning larger quantum circuits into smaller parts that can be executed by current devices. However, this approach often leads to a high sampling overhead, which increases exponentially with the number of cut points. In this paper, we introduce CKVQA, a framework that applies circuit knitting to variational quantum algorithms (VQAs). By employing a quantum circuit architecture search adapted to this scenario, CKVQA aims to minimize the sampling overhead by identifying parameterized quantum circuits that achieve a favorable balance between algorithmic performance and sampling overhead. Additionally, since circuit knitting generates multiple subcircuits, we have developed a subcircuit-level optimization method to accelerate the training of VQAs and reduce overall execution time. We apply this framework to two widely-used VQAs: the Quantum Approximate Optimization Algorithm and the Variational Quantum Eigensolver. Our numerical results demonstrate that the CKVQA framework significantly reduces the sampling overheads while maintaining comparable accuracy to conventional parameterized quantum circuit designs.
- [23] arXiv:2508.03434 [中文pdf, pdf, html, 其他]
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标题： 超导量子比特-耦合器系统的通量串扰表征与缓解标题： Characterizing and Mitigating Flux Crosstalk in Superconducting Qubits-Couplers SystemChen-Hsun Ma, Myrron Albert Callera Aguila, Nien-Yu Li, Li-Chieh Hsiao, Yi-Shiang Huang, Yen-Chun Chen, Teik-Hui Lee, Chin-Chia Chang, Jyh-Yang Wang, Ssu-Yen Huang, Hsi-Sheng Goan, Chiao-Hsuan Wang, Cen-Shawn Wu, Chii-Dong Chen, Chung-Ting Ke评论： 14页，8图，3表主题： 量子物理 (quant-ph) ; 应用物理 (physics.app-ph)
超导量子位已实现了卓越的门保真度，在近年来超过了纠错阈值。 这种改进的一个关键因素是引入可调耦合器，通过频率调节来控制量子位之间的耦合。 朝着容错量子计算发展，增加物理量子位的数量是实现有效纠错码的另一个步骤。 在多量子位架构中，通量控制（Z）线路对于调节量子位和耦合器的频率至关重要。 然而，密集的通量线路会导致磁通串扰，其中施加到一个元件上的磁通会意外地影响相邻的量子位或耦合器。 这种串扰会模糊施加通量偏置时量子位的空闲频率，从而降低门性能和校准精度。 在本研究中，我们在没有为耦合器添加额外读出的情况下，对多量子位耦合器芯片中的通量串扰进行表征并加以抑制。 通过量化量子位和耦合器之间的互感通量引起的频率偏移，我们构建了一个补偿矩阵，能够精确补偿非本地通量，展示了Z线串扰从56.5$\,$permille$\,$减少到0.13$\,$permille$\,$，这接近统计误差。 通量补偿修正了CZ SWAP测量，导致相对于通量偏置的对称映射。 与无串扰计算的CZ SWAP映射相比，测量映射表明我们的方法为耦合器-Transmon系统提供了近零串扰。 这些结果突显了我们方法在增强无通量串扰控制方面的有效性，并支持其在扩展超导量子处理器方面的潜力。
Superconducting qubits have achieved exceptional gate fidelities, exceeding the error-correction threshold in recent years. One key ingredient of such improvement is the introduction of tunable couplers to control the qubit-to-qubit coupling through frequency tuning. Moving toward fault-tolerant quantum computation, increasing the number of physical qubits is another step toward effective error correction codes. Under a multiqubit architecture, flux control (Z) lines are crucial in tuning the frequency of the qubits and couplers. However, dense flux lines result in magnetic flux crosstalk, wherein magnetic flux applied to one element inadvertently affects neighboring qubits or couplers. This crosstalk obscures the idle frequency of the qubit when flux bias is applied, which degrades gate performance and calibration accuracy. In this study, we characterize flux crosstalk and suppress it in a multiqubit-coupler chip with multi-Z lines without adding additional readout for couplers. By quantifying the mutual flux-induced frequency shifts of qubits and couplers, we construct a cancellation matrix that enables precise compensation of non-local flux, demonstrating a substantial reduction in Z-line crosstalk from 56.5$\,$permille$\,$to 0.13$\,$permille$\,$ which is close to statistical error. Flux compensation corrects the CZ SWAP measurement, leading to a symmetric map with respect to flux bias. Compared with a crosstalk-free calculated CZ SWAP map, the measured map indicates that our approach provides a near-zero crosstalk for the coupler-transmon system. These results highlight the effectiveness of our approach in enhancing flux crosstalk-free control and supporting its potential for scaling superconducting quantum processors.
- [24] arXiv:2508.03446 [中文pdf, pdf, html, 其他]
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标题： 量子神经网络在蛋白质结合亲和力预测中的应用标题： Quantum Neural Network applications to Protein Binding Affinity Predictions评论： 16页，7图主题： 量子物理 (quant-ph) ; 机器学习 (cs.LG)
结合能是一种基本的热力学性质，它控制分子相互作用，在医疗保健和自然科学等领域起着关键作用。 它在药物开发、疫苗设计和其他生物医学应用中尤为重要。 多年来，已经开发了各种方法来估计蛋白质结合能，从实验技术到计算方法，机器学习在这一领域做出了重要贡献。 尽管经典计算在构建预测模型方面表现出色，但量子计算在机器学习中的应用已成为一种有前途的替代方案。 量子神经网络（QNNs）已成为研究重点，引发了它们在预测结合能方面的潜在优势的问题。 为了研究这种潜力，本研究通过提出基于多层感知器的量子神经网络的三十种变体来探索该任务的可行性。 这些变体涵盖了三种不同的架构，每种架构都包含十个不同的量子电路来配置其量子层。 这些量子模型的性能与最先进的基于多层感知器的人工神经网络进行了比较，评估了准确性和训练时间。 使用了一个主要数据集进行训练，而另外两个包含完全未见过样本的数据集用于测试。 结果表明，量子模型在一个未见过的数据集上实现了约20%的更高准确性，尽管在其他数据集上的准确性较低。 值得注意的是，量子模型的训练时间比其经典对应物短几个数量级，突显了它们在高效蛋白质结合能预测方面的潜力。
Binding energy is a fundamental thermodynamic property that governs molecular interactions, playing a crucial role in fields such as healthcare and the natural sciences. It is particularly relevant in drug development, vaccine design, and other biomedical applications. Over the years, various methods have been developed to estimate protein binding energy, ranging from experimental techniques to computational approaches, with machine learning making significant contributions to this field. Although classical computing has demonstrated strong results in constructing predictive models, the variation of quantum computing for machine learning has emerged as a promising alternative. Quantum neural networks (QNNs) have gained traction as a research focus, raising the question of their potential advantages in predicting binding energies. To investigate this potential, this study explored the feasibility of QNNs for this task by proposing thirty variations of multilayer perceptron-based quantum neural networks. These variations span three distinct architectures, each incorporating ten different quantum circuits to configure their quantum layers. The performance of these quantum models was compared with that of a state-of-the-art classical multilayer perceptron-based artificial neural network, evaluating both accuracy and training time. A primary dataset was used for training, while two additional datasets containing entirely unseen samples were employed for testing. Results indicate that the quantum models achieved approximately 20% higher accuracy on one unseen dataset, although their accuracy was lower on the other datasets. Notably, quantum models exhibited training times several orders of magnitude shorter than their classical counterparts, highlighting their potential for efficient protein binding energy prediction.
- [25] arXiv:2508.03450 [中文pdf, pdf, html, 其他]
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标题： 腔内局部畴壁之间的宏观纠缠标题： Macroscopic entanglement between localized domain walls inside a cavity评论： 11页，5图主题： 量子物理 (quant-ph) ; 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 光学 (physics.optics)
我们提出了一种方案，用于在纳米磁条中的手性光学腔内保持的两个局域Bloch畴壁之间生成稳定且可调的纠缠。 纠缠是由腔光子与两个被钉扎畴壁的宏观集体模式之间的有效光机械相互作用介导的。 通过控制钉扎势和光学驱动频率，两个宏观畴壁之间的强健稳态纠缠可以超越典型的毫开尔文温度范围。
We present a scheme for generating stable and tunable entanglement between two localized Bloch domain walls in nanomagnetic strips kept inside a chiral optical cavity. The entanglement is mediated by the effective optomechanical interaction between the cavity photons and the two macroscopic, collective modes of the pinned domain walls. By controlling the pinning potential and optical driving frequency, the robust, steady-state entanglement between the two macroscopic domain walls can survive beyond the typical milli-Kelvin temperature range.
- [26] arXiv:2508.03506 [中文pdf, pdf, html, 其他]
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标题： 原子诱导场压缩通过Magnus展开两能级原子的Jaynes-Cummings模型预测标题： Atom-Induced Field Squeezing Predicted by Magnus Expanding the Jaynes-Cummings Model for a Two-Level Atom评论： 6页主题： 量子物理 (quant-ph)
通过对描述两能级原子与单腔模电磁场相互作用的Jaynes-Cummings模型哈密顿量进行二阶Magnus展开，我们发现了超越旋转波近似下的光压缩项。 我们的结果表明，Magnus展开提供了一个系统框架来捕捉由原子引起的光压缩效应。 这些发现表明，在不需要多能级结构或强非线性介质的情况下，为在简单的光-物质系统中工程非经典态提供了新的途径。
By performing up to the second-order Magnus expansion on the Jaynes-Cummings Model Hamiltonian governing the interaction of a two-level atom and a single cavity mode electromagnetic field, we find the term involving the squeezing of light beyond the Rotating Wave Approximation. Our results demonstrate that the Magnus expansion provides a systematic framework to capture atom-induced squeezing effects. These findings suggest new avenues for engineering nonclassical states in simple light-matter systems without requiring multi-level structures or strong nonlinear media.
- [27] arXiv:2508.03525 [中文pdf, pdf, html, 其他]
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标题： 超越局部界限的粗略校准测量纠缠检测标题： Entanglement Detection Beyond Local Bound with Coarse Calibrated measurements主题： 量子物理 (quant-ph)
贝尔测试最初设计用于通过违反局部界限来区分量子理论和局部隐变量模型，也是检测纠缠的常用工具。 为此，可以假设设备的量子描述，并利用可用信息来加强可分离态的界限，这可能超越局部界限，从而实现更高效的纠缠检测。 在这里，我们提出了一种系统的方法，通过考虑仅通过生成非局域相关性而不需要精确量子表征的测量设备，来加强量子比特系统的贝尔不等式，以梅尔金-克利什科-贝尔不等式为例。 在二部和三部系统的情况下，我们根据结构函数推导出可分离态和一般态的上界之间的权衡，以优化纠缠检测。 然后，我们加强了n部分贝尔不等式，以检测表现出多种纠缠结构的状态，如真正的多部分纠缠。 对于一些测量被表征的一般贝尔场景，我们证明可以通过利用纳瓦斯库埃斯-皮罗尼奥-阿辛测试层次结构，通过某些局部相关性来检测纠缠。
Bell's test, initially devised to distinguish quantum theory from local hidden variable models through violations of local bounds, is also a common tool for detecting entanglement. For this purpose, one can assume the quantum description of devices and use available information to strengthen the bound for separable states, which may go beyond the local bound, enabling more efficient entanglement detection. Here we present a systematic approach for strengthening Bell inequalities for qubit systems, using Mermin-Klyshko-Bell inequalities as examples, by considering measurement devices that are coarsely calibrated only by their ability to generate nonlocal correlations without requiring precise quantum characterization. In the case of bipartite and tripartite systems, we derive trade-offs between upper bounds for separable states and general states in terms of structure functions to optimize the entanglement detection. We then strengthen n-partite Bell inequalities for the detection of states exhibiting a diversity of entanglement structures such as genuine multipartite entanglement. For general Bell scenarios with some measurements characterized, we demonstrate that entanglement can also be detected with some local correlations by exploiting the Navascu\'es-Pironio-Ac\'in hierarchy of tests.
- [28] arXiv:2508.03534 [中文pdf, pdf, html, 其他]
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标题： 平移不变矩阵乘积态的稳定器瑞尼熵标题： Stabilizer Rényi Entropy for Translation-Invariant Matrix Product States评论： 19页，4图主题： 量子物理 (quant-ph)
魔法，捕捉量子态偏离稳定子形式的偏差，是支撑量子优势的关键资源。 最近引入的稳定子Rényi熵（SRE）提供了一种易于处理的魔法度量，避免了传统方法的复杂性。 我们研究了平移不变矩阵乘积态（MPS）中的SRE，推导出代表性态的精确表达式，并引入了一种数值稳定的算法，称为bond-DMRG，以计算无限系统中的SRE密度。 应用此方法，我们获得了二维伊辛模型基态的高精度SRE密度。 我们还分析了非局部SRE密度，表明它被纠缠熵的一个通用函数所限制，并进一步证明在注入型MPS中，两站点互信息SRE渐近消失。 我们的工作不仅引入了一种在量子多体系统中提取SRE密度的强大方法，还通过数值揭示了魔法与纠缠之间的基本联系，从而为深入研究它们之间的相互作用奠定了基础。
Magic, capturing the deviation of a quantum state from the stabilizer formalism, is a key resource underpinning the quantum advantage. The recently introduced stabilizer R\'enyi entropy (SRE) offers a tractable measure of magic, avoiding the complexity of conventional methods. We study SRE in translation-invariant matrix product states (MPS), deriving exact expressions for representative states and introducing a numerically stable algorithm, named bond-DMRG, to compute the SRE density in infinite systems. Applying this method, we obtain high-precision SRE densities for the ground state of the one-dimensional Ising model. We also analyze non-local SRE density, showing it is bounded by a universal function of entanglement entropy, and further prove that two-site mutual SRE vanishes asymptotically in injective MPS. Our work not only introduces a powerful method for extracting the SRE density in quantum many-body systems, but also numerically reveals a fundamental connection between magic and entanglement, thereby paving the way for deeper theoretical investigations into their interplay.
- [29] arXiv:2508.03597 [中文pdf, pdf, html, 其他]
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标题： 最优量子$(r,δ)$-局部修复码来自矩阵乘积码标题： Optimal Quantum $(r,δ)$-Locally Repairable Codes From Matrix-Product Codes主题： 量子物理 (quant-ph)
本文研究了从矩阵乘积（MP）码中得到的最优量子$(r,\delta)$-LRCs。 我们建立了MP码成为最优$(r,\delta)$-LRC 的必要充分条件。 基于此，我们给出了具有嵌套分量码的MP码中最优量子$(r,\delta)$-LRCs 的特征，同时也研究了由非嵌套分量码构造的最优量子$(r,\delta)$-LRCs。 通过厄米特自正交和欧几里得自正交的MP码，我们提出了五个具有灵活参数的最优量子$(r,\delta)$-LRCs 的无限族。
This paper studies optimal quantum $(r,\delta)$-LRCs from matrix-product (MP) codes. We establish a necessary and sufficient condition for an MP code to be an optimal $(r,\delta)$-LRC. Based on this, we present a characterization for optimal quantum $(r,\delta)$-LRCs from MP codes with nested constituent codes, and also study optimal quantum $(r,\delta)$-LRCs constructed from MP codes with non-nested constituent codes. Through Hermitian dual-containing and Euclidean dual-containing MP codes, we present five infinite families of optimal quantum $(r,\delta)$-LRCs with flexible parameters.
- [30] arXiv:2508.03652 [中文pdf, pdf, html, 其他]
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标题： 最大非投影测量并不总是对称的信息完备的标题： Maximally non-projective measurements are not always symmetric informationally completeGabriele Cobucci, Raphael Brinster, Shishir Khandelwal, Hermann Kampermann, Dagmar Bruß, Nikolai Wyderka, Armin Tavakoli主题： 量子物理 (quant-ph)
尽管标准量子测量是投影测量，最一般的测量概念由正算子值测度（POVM）表示。 因此，考虑仅能使用投影测量和经典处理的实验者能够多准确地模拟POVM是自然的。 非投影测量中最著名的类别称为对称信息完备（SIC）。 这种测量在更广泛的量子信息理论中无处不在，并且已知是量子比特系统中最强烈的非投影测量。 在这里，我们表明，在量子比特系统之外，SIC特性通常不与最非投影的测量相关联。 为此，我们提出了一种检测真正非投影测量的半定编程准则。 该方法使我们能够确定通用POVM的定量可模拟阈值，并提出了一个关于哪些三量子比特和四量子比特测量是最强烈非投影的猜想。
Whereas standard quantum measurements are projective, the most general notion of a measurement is represented by positive operator-valued measures (POVMs). It is therefore natural to consider how accurately an experimenter with access only to projective measurements and classical processing can simulate POVMs. The most well-known class of non-projective measurements is called symmetric informationally complete (SIC). Such measurements are both ubiquitous in the broader scope of quantum information theory and known to be the most strongly non-projective measurements in qubit systems. Here, we show that beyond qubit systems, the SIC property is in general not associated with the most non-projective measurement. For this, we put forward a semidefinite programming criterion for detecting genuinely non-projective measurements. This method allows us to determine quantitative simulability thresholds for generic POVMs and to put forward a conjecture on which qutrit and ququart measurements that are most strongly non-projective.
新提交 (展示 30 之 30 条目 )
- [31] arXiv:2508.02673 (交叉列表自 cs.CE) [中文pdf, pdf, html, 其他]
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标题： 定量系统分析中决策图的数值误差标题： Numerical Errors in Quantitative System Analysis With Decision Diagrams主题： 计算工程、金融与科学 (cs.CE) ; 数值分析 (math.NA) ; 量子物理 (quant-ph)
决策图（DDs）是一种强大的数据结构，用于解决状态空间爆炸问题，不仅适用于离散系统，也适用于概率和量子系统。 虽然在概率和量子领域中使用的许多DDs使用浮点数，但这并非没有挑战。 浮点计算容易产生微小的舍入误差，这可能会影响结果的正确性和DD压缩的有效性。 在本文中，我们研究了与多终端二进制决策图（MTBDDs）进行矩阵-向量乘法的数值稳定性，即算法对小数值误差的鲁棒性。 矩阵-向量乘法特别重要，因为它用于计算概率和量子系统的后继状态。 我们证明，在某些条件下，MTBDD矩阵-向量乘法算法可以实现数值稳定，尽管在许多MTBDD的实际实现中这些条件并未满足。 此外，我们提供了一个关于量子电路模拟中数值误差的案例研究，该研究表明实际中的数值误差程度在不同实例之间差异很大。
Decision diagrams (DDs) are a powerful data structure that is used to tackle the state-space explosion problem, not only for discrete systems, but for probabilistic and quantum systems as well. While many of the DDs used in the probabilistic and quantum domains make use of floating-point numbers, this is not without challenges. Floating-point computations are subject to small rounding errors, which can affect both the correctness of the result and the effectiveness of the DD's compression. In this paper, we investigate the numerical stability, i.e. the robustness of an algorithm to small numerical errors, of matrix-vector multiplication with multi-terminal binary decision diagrams (MTBDDs). Matrix-vector multiplication is of particular interest because it is the function that computes successor states for both probabilistic and quantum systems. We prove that the MTBDD matrix-vector multiplication algorithm can be made numerically stable under certain conditions, although in many practical implementations of MTBDDs these conditions are not met. Additionally, we provide a case study of the numerical errors in the simulation of quantum circuits, which shows that the extent of numerical errors in practice varies greatly between instances.
- [32] arXiv:2508.02781 (交叉列表自 cond-mat.mes-hall) [中文pdf, pdf, html, 其他]
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标题： 光探测反铁磁磁振子的量子几何标题： Quantum Geometry of Altermagnetic Magnons Probed by Light评论： 9+4页，4+3图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 材料科学 (cond-mat.mtrl-sci) ; 光学 (physics.optics) ; 量子物理 (quant-ph)
具有动量依赖手性的磁振子是反铁磁体的关键特征。 我们确定双圆偏振光作为探测手性反铁磁磁振子的决定性光学探针，选择性地针对由磁振子手性改变引起的量子几何特性。 我们表明，在$d$波反铁磁体中，在倾斜磁场下，反铁磁磁振子实现非平凡的量子几何，导致非线性二阶光-磁振子相互作用增强。 我们发现，双圆脉冲的散射可以探测存在的磁振子量子几何，即使磁振子拓扑是平凡的。 因此，我们的研究结果确立了双圆拉曼响应作为一种识别反铁磁磁振子的首选光学效应。 因此，我们提出了一种通用的实验协议，通过用光检测其磁振子手性模式来区分反铁磁体和反磁铁，而无需考虑底层的磁振子拓扑。
Magnons with momentum-dependent chirality are a key signature of altermagnets. We identify bicircular light as a smoking-gun optical probe for chiral altermagnetic magnons, selectively targeting their quantum geometry induced by an alteration of magnonic chirality. We show that in $d$-wave altermagnets, under a canting magnetic field, the altermagnetic magnons realize a nontrivial quantum geometry, resulting in an enhancement of the nonlinear second-order light-magnon interactions. We find that the scattering of bicircular pulses probes the present magnon quantum geometry, even if the magnonic topology is trivial. Hence, our findings establish bicircular Raman response as an optical effect of choice to identify altermagnetic magnons. As such, we propose a universal experimental protocol to distinguish altermagnets from antiferromagnets by detecting their magnon chirality patterns with light, independently of the underlying magnon topology.
- [33] arXiv:2508.02819 (交叉列表自 cond-mat.dis-nn) [中文pdf, pdf, html, 其他]
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标题： 随机图上的伊辛模型中的量子混沌和复杂性签名标题： Signatures of quantum chaos and complexity in the Ising model on random graphs主题： 无序系统与神经网络 (cond-mat.dis-nn) ; 高能物理 - 理论 (hep-th) ; 量子物理 (quant-ph)
我们研究在随机 Erdős-Rényi 图上的量子退火 Ising 模型中的量子混沌和复杂性的特征。 通过调整图的连通性，动力学可以从局域相经过混沌区域到可积极限。 虽然这种动力学转变反映在光谱特性中，但我们追求更广泛的量子混沌指标，其中一些可以在近期的量子设备上测量。 我们研究从子系统密度矩阵的自然展开中获得的量子态集合的深度热化，作为混沌动力学的指标。 这将量子混沌的分析扩展到了量子态的集合。 此外，我们通过子系统的部分光谱形式因子分析本征态和本征值的相关性，并观察到混沌开始及其系统尺寸依赖性的显著特征，提供了可实验测量的局域化到混沌转变的指标。 作为与局域性无关的探测器，我们表明算符的 Krylov 复杂度在混沌区域也达到最大值，建立了图拓扑与信息散射之间的联系。 最后，我们研究了 Mpemba 效应的量子模拟，其中初始“更热”的状态可以异常快速地热化，这一现象在混沌相中最为清晰地被观察到。 然而，在远离混沌区域时，系统的特点是其与热力学集合的距离随时间在连通性上出现多个交叉。 总体而言，这项工作提供了对混沌的广泛表征，超越了光谱分析并提供了用于基准测试近期量子设备的实际指标。
We investigate signatures of quantum chaos and complexity in the quantum annealing Ising model on random Erd\H{o}s-R\'enyi graphs. By tuning the connectivity of the graph, the dynamics can be driven from a localized phase through a chaotic regime to an integrable limit. While this dynamical transition reflects in the spectral characteristics, we pursue a broader suite of quantum chaos indicators,some of which can be measured on near-term quantum devices. We study deep thermalization of a quantum state ensemble obtained from a natural unraveling of the subsystem density matrix as an indicator of chaotic dynamics. This extends the analysis of quantum chaos to the ensemble of quantum states. Furthermore, we analyze the eigenstate and eigenvalue correlations through the partial spectral form factor of subsystems and observe distinct signatures of the onset of chaos and its system size dependence, providing experimentally measurable indicators of the localization-to-chaos transition. As a locality-independent probe, we show that the Krylov complexity of operators is also maximized in the chaotic regime, providing a link between graph topology and information scrambling. Finally, we investigate a quantum analogue of the Mpemba effect, where initially "hotter" states can thermalize anomalously fast, a phenomenon most cleanly observed within the chaotic phase. However, away from the chaotic regime, the system is distinguished by multiple crossings across connectivity in its distance from the thermal ensemble with time. Collectively, this work presents a broad characterization of chaos, providing insight beyond spectral analysis and practical indicators for benchmarking near-term quantum devices.
- [34] arXiv:2508.02857 (交叉列表自 cs.PL) [中文pdf, pdf, 其他]
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标题： Qunity中高效的组合量子控制流标题： Compositional Quantum Control Flow with Efficient Compilation in Qunity评论： 88页，30图主题： 编程语言 (cs.PL) ; 量子物理 (quant-ph)
大多数现有的量子编程语言都基于量子电路计算模型，因为实现更高级别的抽象尤其具有挑战性——尤其是与量子控制流相关的抽象。 Voichick等人提出的Qunity语言以量子控制构造的形式提供了这样的抽象，并且非常谨慎地确保了最终语言仍然可以实现。 然而，Qunity缺乏一个可用的实现，最初提出的编译过程效率非常低，即使是简单的量子算法也会编译成不合理大的电路。 在这项工作中，我们专注于高效编译高级量子控制流构造，以Qunity作为我们的起点。 我们在Qunity的核心语言之上引入了更广泛的抽象，与现有的控制构造相比，这些抽象提供了有吸引力的权衡。 我们创建了一个完整的Qunity编译器实现，该编译器将高级Qunity代码转换为量子汇编语言OpenQASM 3。 我们开发了多种阶段的Qunity编译过程优化技术，包括低级电路优化以及考虑Qunity程序高级结构的方法，大大减少了编译器使用的量子比特和门的数量。
Most existing quantum programming languages are based on the quantum circuit model of computation, as higher-level abstractions are particularly challenging to implement - especially ones relating to quantum control flow. The Qunity language, proposed by Voichick et al., offered such an abstraction in the form of a quantum control construct, with great care taken to ensure that the resulting language is still realizable. However, Qunity lacked a working implementation, and the originally proposed compilation procedure was very inefficient, with even simple quantum algorithms compiling to unreasonably large circuits. In this work, we focus on the efficient compilation of high-level quantum control flow constructs, using Qunity as our starting point. We introduce a wider range of abstractions on top of Qunity's core language that offer compelling trade-offs compared to its existing control construct. We create a complete implementation of a Qunity compiler, which converts high-level Qunity code into the quantum assembly language OpenQASM 3. We develop optimization techniques for multiple stages of the Qunity compilation procedure, including both low-level circuit optimizations as well as methods that consider the high-level structure of a Qunity program, greatly reducing the number of qubits and gates used by the compiler.
- [35] arXiv:2508.02916 (交叉列表自 hep-ph) [中文pdf, pdf, html, 其他]
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标题： 非相对论性夸克偶素系统的量子自助法标题： Quantum Bootstrap Approach to a Non-Relativistic Potential for Quarkonium systems评论： 11页主题： 高能物理 - 现象学 (hep-ph) ; 高能物理 - 格点 (hep-lat) ; 高能物理 - 理论 (hep-th) ; 量子物理 (quant-ph)
量子自助方法被应用于使用非相对论势近似确定夸克偶素系统的束缚态谱。 该方法将薛定谔方程转化为径向矩$\langle r^m \rangle$的一组代数递归关系，这些矩受到其相应汉克尔矩阵半正定性的约束。 数值实现首先通过计算 charm 介子（$c\bar{c}$）和 bottom 介子（$b\bar{b}$）系统的$1S$和$1P$质心质量来验证，发现与粒子数据组（PDG）实验数据的偏差小于0.5%。 这种分析随后扩展到假设的顶夸克偶素 ($t\bar{t}$) 系统，预测了一个 $1S$ 基态质量为 $M \approx 344.3 \text{ GeV}$。 这个理论质量与ATLAS和CMS合作组最近在 $t\bar{t}$ 截面中观察到的类似共振增强的能级一致。 这一结果为将此实验现象解释为准束缚顶夸克偶素态的形成提供了理论支持，并突显了非相对论势方法对两个大质量夸克系统的预测能力。
The quantum bootstrap method is applied to determine the bound-state spectrum of Quarkonium systems using a non-relativistic potential approximation. The method translates the Schr\"odinger equation into a set of algebraic recursion relations for radial moments $\langle r^m \rangle$, which are constrained by the positive semidefiniteness of their corresponding Hankel matrices. The numerical implementation is first validated by calculating the $1S$ and $1P$ mass centroids for both charmonium ($c\bar{c}$) and bottomonium ($b\bar{b}$) systems, finding deviations of less than 0.5\% from experimental data from the Particle Data Group (PDG). This analysis is then extended to the hypothetical toponium ($t\bar{t}$) system, predicting a $1S$ ground state mass of $M \approx 344.3 \text{ GeV}$. This theoretical mass is in agreement with the energy of the recently observed resonance-like enhancement in the $t\bar{t}$ cross-section by the ATLAS and CMS collaborations. This result provides theoretical support for the interpretation of this experimental phenomenon as the formation of a quasi-bound toponium state and highlights the predictive power of the non-relativistic potential approach for systems of two massive quarks.
- [36] arXiv:2508.03126 (交叉列表自 hep-lat) [中文pdf, pdf, html, 其他]
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标题： 新的格点规范理论计算方法——量子计算和张量网络标题： New computational methods in lattice gauge theory -- quantum computation and tensor networks评论： 10页，6图，第21届国际强子谱学与结构会议（HADRON2025）论文集，特邀报告主题： 高能物理 - 格点 (hep-lat) ; 高能物理 - 现象学 (hep-ph) ; 核理论 (nucl-th) ; 量子物理 (quant-ph)
基于场论的拉格朗日形式主义，过去40年里已经使用大规模经典计算机进行了格点QCD计算。 另一方面，量子计算机的出现使得基于与这些机器兼容的哈密顿形式主义的第一性原理计算方法引起了越来越多的关注。 在本次演讲中，我们将讨论如何利用哈密顿形式主义来计算强子性质的最新结果。
Lattice QCD calculations have been conducted using large-scale classical computers based on the Lagrangian formalism of field theory for the past 40 years. On the other hand, the advent of quantum computers has brought increasing attention to first-principles computational methods based on the Hamiltonian formalism compatible with these machines. In this talk, we discuss recent results on how to calculate hadronic properties using the Hamiltonian formalism.
- [37] arXiv:2508.03219 (交叉列表自 cond-mat.mes-hall) [中文pdf, pdf, html, 其他]
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标题： 量子双极热电性标题： Quantum Bipolar Thermoelectricity主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 超导性 (cond-mat.supr-con) ; 量子物理 (quant-ph)
热电效应通常起源于与能量相关的输运不对称性。 在本文中，我们探讨了一种纯粹的量子热电效应，该效应源于低温量子浴的发射/吸收不对称性。 我们提出了一种间隙不对称的S-I-S'超导隧道结，在热平衡状态下，与低温电磁环境耦合，由于动态库仑阻塞而产生非线性量子双极热电效应。 分析了实际实现的关键性能特征。
Thermoelectricity usually originates from energy-dependent transport asymmetries. In this Letter, we explore a purely quantum thermoelectric effect rooted in the emission/absorption asymmetry of a low-temperature quantum bath. We propose a gap-asymmetric S-I-S' superconducting tunnel junction in thermal equilibrium, coupled to a low-temperature electromagnetic environment, which develops a nonlinear quantum bipolar thermoelectric effect due to the dynamical Coulomb blockade. Key performance features are analyzed for realistic implementations.
- [38] arXiv:2508.03380 (交叉列表自 gr-qc) [中文pdf, pdf, html, 其他]
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标题： 压缩准正则模从非线性引力效应标题： Squeezed Quasinormal Modes from Nonlinear Gravitational Effects评论： 20页，0图主题： 广义相对论与量子宇宙学 (gr-qc) ; 量子物理 (quant-ph)
我们证明，由于非线性引力效应，长寿命黑洞准正则模会变得量子力学压缩。 我们定量估计了施瓦茨希尔德黑洞基本模式的压缩程度。
We demonstrate that long-lived black hole quasi-normal modes become quantum mechanically squeezed due to nonlinear gravitational effects. We estimate the degree of squeezing for the fundamental mode of a Schwarzschild black hole quantitatively.
- [39] arXiv:2508.03491 (交叉列表自 physics.atom-ph) [中文pdf, pdf, html, 其他]
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标题： AION-10：牛津10米原子干涉仪技术设计报告标题： AION-10: Technical Design Report for a 10m Atom Interferometer in OxfordK. Bongs, A. Brzakalik, U. Chauhan, S. Dey, O. Ennis, S. Hedges, T. Hird, M. Holynski, S. Lellouch, M. Langlois, B. Stray, B. Bostwick, J. Chen, Z. Eyler, V. Gibson, T. L. Harte, C. C. Hsu, M. Karzazi, C. Lu, B. Millward, J. Mitchell, N. Mouelle, B. Panchumarthi, J. Scheper, U. Schneider, X. Su, Y. Tang, K. Tkalčec, M. Zeuner, S. Zhang, Y. Zhi, K. Clarke, A. Vick, C. F. A. Baynham, O. Buchmüller, D. Evans, L. Hawkins, R. Hobson, L. Iannizzotto-Venezze, A. Josset, D. Lee, E. Pasatembou, B. E. Sauer, M. R. Tarbutt, T. Walker, L. Badurina, A. Beniwal, D. Blas, J. Carlton, J. Ellis, C. McCabe, G. Parish, D. Pathak Govardhan, V. Vaskonen, T. Bowcock, K. Bridges, A. Carroll, J. Coleman, G. Elertas, S. Hindley, C. Metelko, H. Throssell, J. N. Tinsley, E. Bentine, M. Booth, D. Bortoletto, C. Foot, N. Callaghan, C. Gomez-Monedero, K. Hughes, A. James, T. Leese, A. Lowe, J. March-Russell, J. Sander, J. Schelfhout, I. Shipsey, D. Weatherill, D. Wood, S. N. Balashov, M. G. Bason, K. Hussain, H. Labiad, P. Majewski, A. L. Marchant, D. Newbold, Z. Pan, Z. Tam, T. C. Thornton, T. Valenzuela, M. G. D. van der Grinten, I. Wilmut主题： 原子物理 (physics.atom-ph) ; 天体物理学的仪器与方法 (astro-ph.IM) ; 高能物理 - 实验 (hep-ex) ; 仪器与探测器 (physics.ins-det) ; 量子物理 (quant-ph)
本技术设计报告介绍了AION-10，这是一种位于牛津大学的10米原子干涉仪，使用超冷锶原子进行基本物理的精确测量。 AION-10既是未来更大规模实验的原型，也是一种能够开展自身多样化物理项目的多功能科学仪器。 该设计包括一个10米高的垂直塔，用于容纳两个原子干涉仪源，在超高真空环境中运行。 关键的工程挑战包括实现纳米级的振动稳定性以及精确的磁场控制。 解决方案包括主动振动隔离、专门的磁屏蔽以及使用专业起重设备的模块化组装方法。 详细分析确认该设计满足所有性能要求，在现实操作条件下，关键光学部件有97%的时间保持在我们的规格范围内。 在主机建筑中的真空和振动测量结果验证了该仪器将实现量子传感应用所需的精度。 这项工作建立了将原子干涉测量扩展到更长基线的技术基础，同时创建了一个先进的精密测量设施，可能推动我们对基本物理的理解。
This Technical Design Report presents AION-10, a 10-meter atom interferometer to be located at Oxford University using ultracold strontium atoms to make precision measurements of fundamental physics. AION-10 serves as both a prototype for future larger-scale experiments and a versatile scientific instrument capable of conducting its own diverse physics programme. The design features a 10-meter vertical tower housing two atom interferometer sources in an ultra-high vacuum environment. Key engineering challenges include achieving nanometer-level vibrational stability and precise magnetic field control. Solutions include active vibration isolation, specialized magnetic shielding, and a modular assembly approach using professional lifting equipment. Detailed analysis confirms the design meets all performance requirements, with critical optical components remaining within our specifications 97% of the time under realistic operating conditions. Vacuum and vibration measurements in the host building validate that the instrument will achieve the precision needed for quantum sensing applications. This work establishes the technical foundation for scaling atom interferometry to longer baselines while creating a cutting-edge facility for precision measurements that could advance our understanding of fundamental physics.
- [40] arXiv:2508.03592 (交叉列表自 physics.optics) [中文pdf, pdf, 其他]
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标题： 拓扑等离激元太赫兹光电混频中的频率转换标题： Frequency conversion in topological plasmonic THz photo-mixer评论： 12页，17图，初步论文主题： 光学 (physics.optics) ; 材料科学 (cond-mat.mtrl-sci) ; 仪器与探测器 (physics.ins-det) ; 量子物理 (quant-ph)
我们提出了一个替代解释，用于解释在激光增强的等离子体光电混频器中观察到的相干下转换，该过程涉及红外线、毫米波和微波光子。 我们将提供一条通往该器件完整实验表征的路径。
We propose an alternative explanation for the observed coherent down-conversion in a laser-enabled plasmonic photo-mixer involving infrared, millimeter-wave, microwave photons. We will offer a path toward full experimental characterization of the device.
- [41] arXiv:2508.03659 (交叉列表自 cond-mat.mes-hall) [中文pdf, pdf, html, 其他]
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标题： 一种非侵入性和非绝热的量子麦克斯韦妖标题： A noninvasive and nonadiabatic quantum Maxwell demon评论： 4页以上 + 参考文献和补充材料主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 量子物理 (quant-ph)
一个量子力学麦克斯韦妖被提出在量子点设置中。 该妖通过利用未详细电荷探测器避免连续测量引起的退相干。 通过兰道-泽纳-施泰尔伯格-马约拉纳驱动控制相干隧穿，实现了无需投入功的高效反馈操作。 局部违反第二定律实现了同时发电和冷却。 我们讨论响应电流涨落，以及由于故障产生的妖反作用，发现非绝热区域中的最佳性能。
A quantum mechanical Maxwell demon is proposed in a quantum dot setting. The demon avoids continuous-measurement induced decoherence by exploiting an undetailed charge detector. The control of coherent tunneling via Landau-Zener-St\"uckelberg-Majorana driving allows for efficient feedback operations with no work invested. The local violation of the second law achieves simultaneous power generation and cooling. We discuss the response current fluctuations, and the demon backaction deriving from failures, finding optimal performance in the nonadiabatic regime.
交叉提交 (展示 11 之 11 条目 )
- [42] arXiv:2310.03011 (替换) [中文pdf, pdf, 其他]
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标题： 量子算法：应用与端到端复杂性的综述标题： Quantum algorithms: A survey of applications and end-to-end complexitiesAlexander M. Dalzell, Sam McArdle, Mario Berta, Przemyslaw Bienias, Chi-Fang Chen, András Gilyén, Connor T. Hann, Michael J. Kastoryano, Emil T. Khabiboulline, Aleksander Kubica, Grant Salton, Samson Wang, Fernando G. S. L. Brandão评论： 带有类似维基的模块化结构的调查文档。416页，包括参考文献和子参考文献。v2：包含截至2024年中期的更新以及在进行自填式非匿名同行评审流程后的修订。2025年4月由剑桥大学出版社作为开放获取书籍出版。主题： 量子物理 (quant-ph)
量子计算机的预期应用涵盖科学和工业领域，从量子化学和多体物理到优化、金融和机器学习。 这些领域的量子解决方案通常将多个量子算法原语组合成一个整体的量子算法，然后必须结合量子错误校正和容错方法才能在量子硬件上正确实现。 因此，评估特定应用从量子计算中获得的好处可能很困难，因为各种方法通常对底层原语及其复杂性的细节非常敏感。 在此，我们对几种量子算法的潜在应用领域及其底层算法原语进行了综述，并仔细考虑了技术上的注意事项和细微差别。 我们通过明确定义所解决问题以及输入输出模型，实例化所有“预言机”，并明确所有隐藏成本，以“端到端”的方式概述每个领域的挑战和机遇。 我们还将量子解决方案与最先进的经典方法和复杂性理论限制进行比较，以评估可能的量子加速效果。 该综述以模块化、类似维基的方式编写，以便于内容导航。 每个原语和应用领域都在独立的章节中讨论，有自己的参考文献和嵌入的超链接，指向其他相关部分。 这种结构反映了涉及多个抽象层次的复杂量子算法的结构，并能够快速评估当子程序改变时端到端复杂性如何受到影响。
The anticipated applications of quantum computers span across science and industry, ranging from quantum chemistry and many-body physics to optimization, finance, and machine learning. Proposed quantum solutions in these areas typically combine multiple quantum algorithmic primitives into an overall quantum algorithm, which must then incorporate the methods of quantum error correction and fault tolerance to be implemented correctly on quantum hardware. As such, it can be difficult to assess how much a particular application benefits from quantum computing, as the various approaches are often sensitive to intricate technical details about the underlying primitives and their complexities. Here we present a survey of several potential application areas of quantum algorithms and their underlying algorithmic primitives, carefully considering technical caveats and subtleties. We outline the challenges and opportunities in each area in an "end-to-end" fashion by clearly defining the problem being solved alongside the input-output model, instantiating all "oracles," and spelling out all hidden costs. We also compare quantum solutions against state-of-the-art classical methods and complexity-theoretic limitations to evaluate possible quantum speedups. The survey is written in a modular, wiki-like fashion to facilitate navigation of the content. Each primitive and application area is discussed in a standalone section, with its own bibliography of references and embedded hyperlinks that direct to other relevant sections. This structure mirrors that of complex quantum algorithms that involve several layers of abstraction, and it enables rapid evaluation of how end-to-end complexities are impacted when subroutines are altered.
- [43] arXiv:2311.10433 (替换) [中文pdf, pdf, html, 其他]
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标题： 从张量网络视角出发的直接约束任务调度优化标题： Task Scheduling Optimization with Direct Constraints from a Tensor Network Perspective评论： 14页，15图，改进版，包含更多实验、分析、新解释和演示，以及开源代码主题： 量子物理 (quant-ph) ; 新兴技术 (cs.ET)
这项工作提出了一种使用量子启发张量网络技术进行工业工厂任务优化的新方法。 该方法在一组机器上获得具有定向约束的任务的最佳组合。 通过此方法，提供了问题的精确和显式解。 该算法构建了张量的张量网络表示，该表示提供了问题的解。 为了减少解计算的计算复杂性，对该方法进行了改进，使用了问题预处理、逻辑约束凝聚的新技术、利用先前计算结果优化值确定技术、重用中间计算以及约束的迭代关系。 提出了三种计算算法：主算法、仅添加最少必要约束的迭代算法，以及将迭代算法与基本遗传算法结合的遗传算法。 最后，实现了两种算法的简化版本，并测试了它们的性能，所有结果均可公开获取。
This work presents a novel method for task optimization in industrial plants using quantum-inspired tensor network technology. This method obtains the best possible combination of tasks on a set of machines with directed constraints. With this method, an exact and explicit solution of the problem is provided. This algorithm constructs a tensor network representation of the tensor which provides the solution of the problem. This method is improved in order to reduce the computational complexity of the solution computation, using problem preprocessing, new techniques of condensation of logical constraints, optimization of the value determination technique with previously calculated results, reuse of intermediate computations, and iterative relations for constraints. Three algorithms for computation are presented: the main algorithm, the iterative algorithm which adds only the minimal amount of necessary constraints, and the genetic algorithm which combines the iterative algorithm with basic genetic algorithms. Finally, a simple version of both algorithms was implemented, and their performance was tested, all publicly available.
- [44] arXiv:2311.16819 (替换) [中文pdf, pdf, html, 其他]
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标题： 通过非谐波势调制对连续系统进行量子控制标题： Quantum control of continuous systems via nonharmonic potential modulation评论： 23页，28图主题： 量子物理 (quant-ph)
我们提出一种理论方案，用于制备和操控受限于非谐势的单个连续变量自由度的状态。 通过最优控制调制势的位移和深度，我们展示了非高斯态的生成，包括数态、Gottesman-Kitaev-Preskill态、多腿猫态和立方相态，以及在选定的两能级子空间内实现任意酉操作。 此外，我们提出了单次正交态鉴别、算法冷却和校正非线性演化的方法。 我们分析了该控制方案对噪声的鲁棒性。 由于所有提出的协议仅依赖于有效非谐势景观的精确调制，因此它们适用于多个连续变量系统的实验，包括光学镊子或晶格中单个粒子的运动，或电路量子电动力学中的电流。
We present a theoretical proposal for preparing and manipulating a state of a single continuous-variable degree of freedom confined to a nonharmonic potential. By utilizing optimally controlled modulation of the potential's position and depth, we demonstrate the generation of non-Gaussian states, including Fock, Gottesman-Kitaev-Preskill, multi-legged-cat, and cubic-phase states, as well as the implementation of arbitrary unitaries within a selected two-level subspace. Additionally, we propose protocols for single-shot orthogonal state discrimination, algorithmic cooling, and correcting for nonlinear evolution. We analyze the robustness of this control scheme against noise. Since all the presented protocols rely solely on the precise modulation of the effective nonharmonic potential landscape, they are relevant to several experiments with continuous-variable systems, including the motion of a single particle in an optical tweezer or lattice, or current in circuit quantum electrodynamics.
- [45] arXiv:2406.04190 (替换) [中文pdf, pdf, html, 其他]
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标题： 通过稳定子熵的普遍饱和来探测量子复杂性标题： Probing quantum complexity via universal saturation of stabilizer entropies评论： 12+5页，6+5图。更正了公式28中的拼写错误期刊参考： 量子9，1801（2025）主题： 量子物理 (quant-ph) ; 统计力学 (cond-mat.stat-mech)
非稳定化或“魔法”是量子计算的关键资源，也是实现量子优势的必要条件。 非克莱夫操作将稳定化态转化为有资源的状态，其中非稳定化的量由稳定化瑞尼熵（SREs）等资源度量来量化。 在这里，我们表明SREs在非克莱夫操作的临界数量时达到最大值。 接近临界点时，SREs表现出普遍行为。 值得注意的是，SRE的导数在相同点交叉，与量子比特数量无关，并且可以缩放为一条曲线。 我们发现临界点非平凡地依赖于瑞尼指数$\alpha$。 对于掺杂T门的随机克莱夫电路，临界T门密度独立于$\alpha$。 相反，对于随机哈密顿演化，临界时间对于$\alpha>1$线性随量子比特数量变化，而对于$\alpha<1$是一个常数。 This highlights that $\alpha$-SREs reveal fundamentally different aspects of nonstabilizerness depending on $\alpha$: $\alpha$-SREs with $\alpha<1$ relate to Clifford simulation complexity, while $\alpha>1$ probe the distance to the closest stabilizer state and approximate state certification cost via Pauli measurements. As technical contributions, we observe that the Pauli spectrum of random evolution can be approximated by two highly concentrated peaks which allows us to compute its SRE. Further, we introduce a class of random evolution that can be expressed as random Clifford circuits and rotations, where we provide its exact SRE. Our results opens up new approaches to characterize the complexity of quantum systems.
Nonstabilizerness or `magic' is a key resource for quantum computing and a necessary condition for quantum advantage. Non-Clifford operations turn stabilizer states into resourceful states, where the amount of nonstabilizerness is quantified by resource measures such as stabilizer R\'enyi entropies (SREs). Here, we show that SREs saturate their maximum value at a critical number of non-Clifford operations. Close to the critical point SREs show universal behavior. Remarkably, the derivative of the SRE crosses at the same point independent of the number of qubits and can be rescaled onto a single curve. We find that the critical point depends non-trivially on R\'enyi index $\alpha$. For random Clifford circuits doped with T-gates, the critical T-gate density scales independently of $\alpha$. In contrast, for random Hamiltonian evolution, the critical time scales linearly with qubit number for $\alpha>1$, while is a constant for $\alpha<1$. This highlights that $\alpha$-SREs reveal fundamentally different aspects of nonstabilizerness depending on $\alpha$: $\alpha$-SREs with $\alpha<1$ relate to Clifford simulation complexity, while $\alpha>1$ probe the distance to the closest stabilizer state and approximate state certification cost via Pauli measurements. As technical contributions, we observe that the Pauli spectrum of random evolution can be approximated by two highly concentrated peaks which allows us to compute its SRE. Further, we introduce a class of random evolution that can be expressed as random Clifford circuits and rotations, where we provide its exact SRE. Our results opens up new approaches to characterize the complexity of quantum systems.
- [46] arXiv:2406.17653 (替换) [中文pdf, pdf, html, 其他]
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标题： 通用量子计算的低开销横向容错标题： Low-Overhead Transversal Fault Tolerance for Universal Quantum ComputationHengyun Zhou, Chen Zhao, Madelyn Cain, Dolev Bluvstein, Nishad Maskara, Casey Duckering, Hong-Ye Hu, Sheng-Tao Wang, Aleksander Kubica, Mikhail D. Lukin评论： v2：添加了仿真中使用的电路链接，改进了容错构造的展示主题： 量子物理 (quant-ph)
快速、可靠的逻辑操作对于实现有用的量子计算机至关重要。通过将逻辑量子比特冗余地编码到许多物理量子比特中，并使用联合测量来检测和纠正错误，可以实现低逻辑错误率。然而，对于许多实际的量子纠错（QEC）码，如表面码，由于联合测量错误，标准构造需要多个提取轮次——大约为码距$d$——来进行容错计算，特别是考虑到容错态制备。在这里，我们表明，对于包括带有魔术态输入和前馈的表面码在内的广泛类别的QEC码，逻辑操作可以通过仅恒定数量的提取轮次进行容错执行，以实现“横跨算法容错”。通过将横跨操作与新颖的相关解码策略相结合，尽管只能获得部分联合信息，我们证明了理想逻辑测量分布的偏差可以在距离上呈指数级小，即使由于测量错误，瞬时量子态无法接近逻辑码字。我们通过在一系列相关设置中的电路级模拟补充了这一证明，展示了我们方法的容错性和竞争力。我们的工作为量子容错理论提供了新的见解，并有可能将实际容错量子计算的空间-时间成本降低一个数量级以上。
Fast, reliable logical operations are essential for realizing useful quantum computers. By redundantly encoding logical qubits into many physical qubits and using syndrome measurements to detect and correct errors, one can achieve low logical error rates. However, for many practical quantum error correcting (QEC) codes such as the surface code, due to syndrome measurement errors, standard constructions require multiple extraction rounds -- on the order of the code distance $d$ -- for fault-tolerant computation, particularly considering fault-tolerant state preparation. Here, we show that logical operations can be performed fault-tolerantly with only a constant number of extraction rounds for a broad class of QEC codes, including the surface code with magic state inputs and feed-forward, to achieve ``transversal algorithmic fault tolerance". Through the combination of transversal operations and novel strategies for correlated decoding, despite only having access to partial syndrome information, we prove that the deviation from the ideal logical measurement distribution can be made exponentially small in the distance, even if the instantaneous quantum state cannot be made close to a logical codeword due to measurement errors. We supplement this proof with circuit-level simulations in a range of relevant settings, demonstrating the fault tolerance and competitive performance of our approach. Our work sheds new light on the theory of quantum fault tolerance and has the potential to reduce the space-time cost of practical fault-tolerant quantum computation by over an order of magnitude.
- [47] arXiv:2407.04537 (替换) [中文pdf, pdf, html, 其他]
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标题： 量子力学作为没有隐变量和测量问题的现实局部理论标题： Quantum Mechanics as a Realistic Local Theory without Hidden Variables and Measurement Problem评论： 11页，无图表主题： 量子物理 (quant-ph)
表明现代量子力学的任何一致解释都是不可能的，因为其公理体系是矛盾且不完整的：其规定在薛定谔表象中波函数总是描述纯态，以及描述纯态的波函数只对可观测量的值施加统计限制，是错误的。
It is shown that any consistent interpretation of modern quantum mechanics is impossible, since its axiomatics is contradictory and incomplete: its provisions that the wave function in the Schr\"{o}dinger representation always describes pure states, and the wave function describing pure states imposes only statistical restrictions on the values of observables, are erroneous.
- [48] arXiv:2407.11926 (替换) [中文pdf, pdf, html, 其他]
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标题： 远离完美的量子纠错与（超不变）偶对码标题： Far from Perfect: Quantum Error Correction with (Hyperinvariant) Evenbly Codes评论： 30页，13图主题： 量子物理 (quant-ph) ; 高能物理 - 理论 (hep-th)
我们引入了一类新的量子比特码，称为Evenbly码，这是基于之前提出的超不变张量网络的建议。其张量网络描述由局部的非完美张量组成，这些张量描述了交错的CSS码和哈达玛门，放置在双曲$\{p,q\}$几何结构上，具有偶数$q\geq 4$，从而产生了一个无限大的子系统码类别。我们构建了一个$\{5,4\}$流形的例子，并描述了逻辑规范固定策略，这些策略导致不同的速率$k/n$和距离$d$，我们进行了分析计算，发现距离范围从$d=2$到$d \sim n^{2/3}$。在擦除、去极化和纯保罗噪声信道下研究阈值性能，我们发现该码在代码容量模型中表现出约19.1%的去极化噪声阈值，在适当的规范下，纯保罗和擦除信道中的阈值为50%。 我们还测试了一个常数速率版本，使用$k/n = 0.125$，在擦除信道下发现出色的错误鲁棒性（约40%）。 这些以及其他设置的恢复率在最优解码器以及更高效但非最优的贪心解码器下进行了研究。 我们还考虑了超越CSS张量构造的推广，计算了其他双曲几何的错误率和阈值，并讨论了与全息体/边界对偶性的关系。 我们的工作表明，Evenbly码可能在实际量子计算应用中显示出前景。
We introduce a new class of qubit codes that we call Evenbly codes, building on a previous proposal of hyperinvariant tensor networks. Its tensor network description consists of local, non-perfect tensors describing CSS codes interspersed with Hadamard gates, placed on a hyperbolic $\{p,q\}$ geometry with even $q\geq 4$, yielding an infinitely large class of subsystem codes. We construct an example for a $\{5,4\}$ manifold and describe strategies of logical gauge fixing that lead to different rates $k/n$ and distances $d$, which we calculate analytically, finding distances which range from $d=2$ to $d \sim n^{2/3}$. Investigating threshold performance under erasure, depolarizing, and pure Pauli noise channels, we find that the code exhibits a depolarizing noise threshold of about 19.1% in the code-capacity model and 50% for pure Pauli and erasure channels under suitable gauges. We also test a constant-rate version with $k/n = 0.125$, finding excellent error resilience (about 40%) under the erasure channel. Recovery rates for these and other settings are studied both under an optimal decoder as well as a more efficient but non-optimal greedy decoder. We also consider generalizations beyond the CSS tensor construction, compute error rates and thresholds for other hyperbolic geometries, and discuss the relationship to holographic bulk/boundary dualities. Our work indicates that Evenbly codes may show promise for practical quantum computing applications.
- [49] arXiv:2408.00557 (替换) [中文pdf, pdf, html, 其他]
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标题： 端到端协议用于高质量QAOA参数的少量测量标题： End-to-End Protocol for High-Quality QAOA Parameters with Few Shots评论： 13+2页，11+3图，已被《物理评论研究》接收主题： 量子物理 (quant-ph) ; 新兴技术 (cs.ET)
量子近似优化算法（QAOA）是一种用于组合优化的量子启发式算法，已被证明在某些问题上比最先进的经典求解器具有更好的扩展性。 对于给定的问题实例，QAOA的性能在很大程度上取决于参数的选择。 虽然在许多情况下可以得到平均情况下的最优参数，但通过对给定实例微调这些参数可以获得显著的性能提升。 然而，当电路执行次数（shots）有限时，这项任务尤其具有挑战性。 在这项工作中，我们开发了一个端到端的协议，结合了多种参数设置和微调技术。 我们使用大规模数值实验来优化受限于shots的协议，并观察到内部模型最简单的优化器（线性）表现最好。 我们在一个离子阱处理器上实现了优化的流程，使用最多32个量子比特和5个QAOA层，并证明该流程对少量硬件噪声具有鲁棒性。 据我们所知，这些是在离子阱处理器上关于QAOA参数微调的最大规模演示，就2量子比特门的数量而言。
The quantum approximate optimization algorithm (QAOA) is a quantum heuristic for combinatorial optimization that has been demonstrated to scale better than state-of-the-art classical solvers for some problems. For a given problem instance, QAOA performance depends crucially on the choice of the parameters. While average-case optimal parameters are available in many cases, meaningful performance gains can be obtained by fine-tuning these parameters for a given instance. This task is especially challenging, however, when the number of circuit executions (shots) is limited. In this work, we develop an end-to-end protocol that combines multiple parameter settings and fine-tuning techniques. We use large-scale numerical experiments to optimize the protocol for the shot-limited setting and observe that optimizers with the simplest internal model (linear) perform best. We implement the optimized pipeline on a trapped-ion processor using up to 32 qubits and 5 QAOA layers, and we demonstrate that the pipeline is robust to small amounts of hardware noise. To the best of our knowledge, these are the largest demonstrations of QAOA parameter fine-tuning on a trapped-ion processor in terms of 2-qubit gate count.
- [50] arXiv:2409.01440 (替换) [中文pdf, pdf, html, 其他]
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标题： 一种在电路级噪声下用于量子LDPC码的近线性时间解码算法标题： An almost-linear time decoding algorithm for quantum LDPC codes under circuit-level noise评论： 18页，8张图。在V2版本中，我们更新了双变量自行车码的结果，增加了这些码的定时分析、表面码性能以及稀疏化过程的详细分析主题： 量子物理 (quant-ph)
容错量子计算机必须与经典协处理器一起设计，以实时解码量子纠错测量信息。 在本工作中，我们引入了置信传播加有序 Tanner 森林（BP+OTF）算法，作为量子低密度奇偶校验码的近线性时间解码器。 OTF 后处理阶段从解码图中移除量子比特，直到它具有树状结构。 如果结果无环 OTF 图支持可以生成联合效应的一组量子比特，则 BP 解码保证会收敛。 为了在电路级噪声下提高性能，我们引入了一种对检测器错误模型进行稀疏化的方法。 该方法使用转移矩阵将来自完整检测器图的软信息映射到稀疏图中，保留来自联合效应电路的关键错误传播信息。 我们的 BP+OTF 实现首先在完整检测器图上应用标准 BP，然后在稀疏图上进行 BP+OTF 后处理。 数值模拟表明，BP+OTF 解码器在双变量自行车码和表面码上分别实现了与最先进的基于反转和匹配解码器相似的逻辑错误抑制效果，同时在整个阶段保持几乎线性的时间复杂度。
Fault-tolerant quantum computers must be designed in conjunction with classical co-processors that decode quantum error correction measurement information in real-time. In this work, we introduce the belief propagation plus ordered Tanner forest (BP+OTF) algorithm as an almost-linear time decoder for quantum low-density parity-check codes. The OTF post-processing stage removes qubits from the decoding graph until it has a tree-like structure. Provided that the resultant loop-free OTF graph supports a subset of qubits that can generate the syndrome, BP decoding is then guaranteed to converge. To enhance performance under circuit-level noise, we introduce a technique for sparsifying detector error models. This method uses a transfer matrix to map soft information from the full detector graph to the sparsified graph, preserving critical error propagation information from the syndrome extraction circuit. Our BP+OTF implementation first applies standard BP to the full detector graph, followed by BP+OTF post-processing on the sparsified graph. Numerical simulations show that the BP+OTF decoder achieves similar logical error suppression compared to state-of-the-art inversion-based and matching decoders for bivariate bicycle and surface codes, respectively, while maintaining almost-linear runtime complexity across all stages.
- [51] arXiv:2409.17075 (替换) [中文pdf, pdf, html, 其他]
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标题： 使用单光子纠缠的远距离无设备量子密钥分发标题： Long-distance device-independent quantum key distribution using single-photon entanglement主题： 量子物理 (quant-ph)
设备无关的量子密钥分发（DIQKD）提供了最强形式的量子安全，因为它允许两个诚实用户在使用完全未表征的量子设备时建立安全的通信信道。 DIQKD的安全性证明来自于贝尔不等式的违反，通过断言非定域性的存在来减轻侧信道攻击。 这种增强的安全性带来了具有挑战性的实现，尤其是在长距离情况下，因为损耗使得贝尔测试难以成功进行。 在此，我们提出了一种光子实现的DIQKD，利用了在诚实用户之间单光子路径纠缠态的预警制备。 基于单光子干涉效应，获得的保密密钥速率与量子信道传输率的平方根成比例。 这使得在长达数百公里的距离内产生正的密钥速率，使所提出的设置成为在量子网络中保障远距离通信的有前景的候选方案。
Device-independent quantum key distribution (DIQKD) provides the strongest form of quantum security, as it allows two honest users to establish secure communication channels even when using fully uncharacterized quantum devices. The security proof of DIQKD is derived from the violation of a Bell inequality, mitigating side-channel attacks by asserting the presence of nonlocality. This enhanced security comes at the cost of a challenging implementation, especially over long distances, as losses make Bell tests difficult to conduct successfully. Here, we propose a photonic realization of DIQKD, utilizing a heralded preparation of a single-photon path entangled state between the honest users. Being based on single-photon interference effects, the obtained secret key rate scales with the square root of the quantum channel transmittance. This leads to positive key rates over distances of up to hundreds of kilometers, making the proposed setup a promising candidate for securing long-distance communication in quantum networks.
- [52] arXiv:2410.01881 (替换) [中文pdf, pdf, html, 其他]
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标题： 量子计量学在相关噪声存在下的普遍界限标题： Universal bounds for quantum metrology in the presence of correlated noise评论： 新版本包含新示例：碰撞热力学模型主题： 量子物理 (quant-ph)
我们推导了涉及时间或空间相关性的通用量子计量模型的基本界限（数学上由量子梳描述），在涉及大量探测器或传感通道的极限情况下，这些界限可以有效地计算。 尽管这些界限在一般情况下不一定紧密，但可以通过增加过程的数值复杂度来系统地提高其紧密性。 有趣的是，这种方法对于无关联通道也给出了比当前最佳更好的界限。 我们将该界限应用于研究存在时间相关去相位情况下的最一般的自适应相位估计模型的极限。 我们考虑了与信号平行（无海森堡极限）和垂直（可能实现海森堡极限）的去相位。 在前一种情况下，我们的新界限表明负相关是有益的；在后一种情况下，我们提供了界限紧密的证据。 我们还将这些界限应用于碰撞热计量，即对环境参数的估计，表明纠缠探测器可能只提供有限的优势。
We derive fundamental bounds for general quantum metrological models involving both temporal or spatial correlations (mathematically described by quantum combs), which may be effectively computed in the limit of a large number of probes or sensing channels involved. Although the bounds are not guaranteed to be tight in general, their tightness may be systematically increased by increasing numerical complexity of the procedure. Interestingly, this approach yields bounds tighter than the state of the art also for uncorrelated channels. We apply the bound to study the limits for the most general adaptive phase estimation models in the presence of temporally correlated dephasing. We consider dephasing both parallel (no Heisenberg scaling) and perpendicular (Heisenberg scaling possible) to the signal. In the former case our new bounds show that negative correlations are beneficial, for the latter we show evidence that the bounds are tight. We also apply the bounds to collisional thermometry, i.e. estimation of a parameter of the environment, showing evidence that entangled probes may provide only a limited advantage.
- [53] arXiv:2411.09465 (替换) [中文pdf, pdf, html, 其他]
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标题： 通过光子诱导激发共振在腔中感知多原子网络标题： Sensing multiatom networks in cavities via photon-induced excitation resonance期刊参考： 量子科学与技术 10 (3), 035006 (2025)主题： 量子物理 (quant-ph)
我们探索了由偶极-偶极相互作用的原子网络共享的单光子激发在空间和时间上的分布，这些原子也耦合到一个共同的光子场模。 时间平均分布显示激发部分被限制在初始激发的原子附近。 这种限制与网络的光子修饰能级在交叉点处的激发共振有关。 预测的光子诱导的多原子束缚激发（PIMATE）对原子位置无序敏感，这会加宽激发共振并将其转化为避让交叉。 PIMATE被证明能够有效地和准确地感知多原子网络及其无序。
We explore the distribution in space and time of a single-photon excitation shared by a network of dipole-dipole interacting atoms that are also coupled to a common photonic field mode. Time-averaged distributions reveal partial trapping of the excitation near the initially excited atom. This trapping is associated with resonances of the excitation at crossing points of the photon-dressed energy eigenvalues of the network. The predicted photon-induced many-atom trapped excitation (PIMATE) is sensitive to atomic position disorder which broadens the excitation resonances and transforms them to avoided crossings. PIMATE is shown to allow highly effective and accurate sensing of multi-atom networks and their disorder.
- [54] arXiv:2411.17817 (替换) [中文pdf, pdf, html, 其他]
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标题： 用扭秤测试半经典引力效应的第一个结果标题： First result for testing semiclassical gravity effect with a torsion balanceTianliang Yan (1), Yubao Liu (2), Leonid Prokhorov (1), Jiri Smetana (1), Haixing Miao (3), Yiqiu Ma (2), Vincent Boyer (1), Denis Martynov (1) ((1) University of Birmingham, School of Physics and Astronomy, Birmingham, United Kingdom. (2) Center for Gravitational Experiment, Hubei Key Laboratory of Gravitation and Quantum Physics, School of Physics, Huazhong University of Science and Technology, Wuhan, China. (3) State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, China)期刊参考： 物理评论D，2025，111（8）：082007主题： 量子物理 (quant-ph)
薛定谔-牛顿方程是一种将量子力学与经典引力联系起来的理论框架，它预测引力可能在低频机械系统中引起可测量的偏差——这是基础物理学前沿的一个引人入胜的假设。 在本研究中，我们开发并操作了一个先进的光机械平台来研究这些效应。 该系统结合了一个精细度超过350000的光学腔和一个具有超低本征频率0.6mHz的扭摆，实现了超过50000的高机械Q因子。 我们收集了3个月的数据，在薛定谔-牛顿频率2.5mHz处达到了0.3urad/rtHz的灵敏度，此时可能会出现与标准量子力学的偏差。 尽管没有找到支持半经典引力的证据，但我们确定了此类测试中的关键挑战，并提出了新的实验方法以推进这一研究方向。 这项工作展示了精密光机械技术在探测量子力学与引力相互作用方面的潜力。
The Schr\"odinger-Newton equation, a theoretical framework connecting quantum mechanics with classical gravity, predicts that gravity may induce measurable deviations in low-frequency mechanical systems-an intriguing hypothesis at the frontier of fundamental physics. In this study, we developed and operated an advanced optomechanical platform to investigate these effects. The system integrates an optical cavity with finesse over 350000 and a torsion pendulum with an ultra-low eigenfrequency of 0.6mHz, achieving a high mechanical Q-factor exceeding 50000. We collected data for 3 months and reached a sensitivity of 0.3urad/rtHz at the Schr\"odinger-Newton frequency of 2.5mHz where deviations from the standard quantum mechanics may occur. While no evidence supporting semiclassical gravity was found, we identify key challenges in such tests and propose new experimental approaches to advance this line of inquiry. This work demonstrates the potential of precision optomechanics to probe the interplay between quantum mechanics and gravity.
- [55] arXiv:2502.02643 (替换) [中文pdf, pdf, html, 其他]
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标题： 用时变势局域量子场标题： Localizing quantum fields with time-dependent potentials评论： 18页（包括1个附录），13幅图，RevTex 4.2。V2已更新以匹配已发表版本期刊参考： 物理评论D 111，105029（2025）主题： 量子物理 (quant-ph) ; 广义相对论与量子宇宙学 (gr-qc)
在本文中，我们研究通过时间依赖势动态增长腔壁来局部化量子场自由度的影响。 我们利用我们的结果表明，可以在不引入局部化模式中显著混合性的情况下实现这一点。 我们讨论了这如何解决先前文献中提出的担忧，即量子场论中常规态的高度纠缠可能阻碍使用局部化相对论探测器的相对论量子信息协议。
In this paper we study the effect of localizing quantum field degrees of freedom by dynamically growing cavity walls through a time-dependent potential. We use our results to show that it is possible to do this without introducing non-negligible mixedness in localized modes of the field. We discuss how this addresses the concerns, raised in previous literature, that the high degree of entanglement of regular states in QFT may hinder relativistic quantum information protocols that make use of localized relativistic probes.
- [56] arXiv:2502.19715 (替换) [中文pdf, pdf, 其他]
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标题： 非互易纠缠通过动态环绕一个节点标题： Nonreciprocal Entanglement by Dynamically Encircling a Nexus评论： 8页，4图主题： 量子物理 (quant-ph)
非互易纠缠，以其固有的鲁棒性操作为特征，是量子信息处理和通信的核心。 然而，实现具有稳定性和抗环境波动能力的非互易纠缠仍然是一个巨大的挑战。 在这里，我们提出了一种通用的非线性机制，通过利用双稳态现象，在耗散光机械系统中构建无磁非互易性，这种现象在非线性物理系统中普遍存在。 通过动态环绕双稳态的奇点，即由双稳态表面汇聚的尖点，我们获得了非互易位移，并利用它来实现鲁棒的非互易纠缠。 由于双稳态的独特景观，我们的非互易位移和纠缠在闭环操作中表现出稳定性和鲁棒性。 我们的工作为利用非线性实现非互易量子信息处理提供了一个基础框架。 它为探索非互易量子信息处理以及设计具有非线性的抗反作用量子计量学开辟了新途径。
Nonreciprocal entanglement, characterized by inherently robust operation, is a cornerstone for quantum information processing and communications. However, it remains a great challenge to achieve nonreciprocal entanglement characterized by stability and robustness against environmental fluctuations. Here, we propose a universal nonlinear mechanism to engineer magnetic-free nonreciprocity in dissipative optomechanics by utilizing bistability, a phenomenon ubiquitous across nonlinear physical systems. By dynamically encircling the nexus of bistability, a cusp converged by the bistable surfaces, we obtain nonreciprocal displacement and then utilize it to achieve robust nonreciprocal entanglement. Owing to the unique landscape of bistability, our nonreciprocal displacement and entanglements exhibit stability and robustness through closed-loop operations. Our work presents a foundational framework for leveraging nonlinearity to achieve nonreciprocal quantum information processing. It paves new avenues for exploring nonreciprocal quantum information processing and designing backaction-immune quantum metrology with nonlinearity.
- [57] arXiv:2503.05655 (替换) [中文pdf, pdf, html, 其他]
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标题： 复杂量子网络中的记忆保持与协作屏蔽标题： Memory preservation and cooperative shielding in complex quantum networks评论： 33页，6图；增加了通过功率谱和幂律依赖跳跃读取的记忆效应的更详细分析主题： 量子物理 (quant-ph)
复杂量子网络是建模传输现象的强大工具，特别是在生物系统中，并能够研究多体量子系统的涌现现象。高连通性和长程相互作用对系统动力学施加了强约束。在这里，我们研究由典型的XXZ哈密顿量描述的量子网络的传输特性，该网络具有非平凡的图连通性和拓扑结构以及长程相互作用。我们展示了长程相互作用如何引起保持记忆的效果，并由于协同屏蔽而强烈影响激发态的扩展。我们描述了在全连接的规则网络中距离无关耦合的记忆保持效应。确实，初始注入的激发态数量的记忆在长时间内得到保持，并编码在动力学中的频率数量中。有趣的是，我们发现记忆保持效应也出现在不太规则的图中，例如具有幂律节点连通性或复杂、小世界类型的架构的量子网络。我们讨论了这些特性在与生物学相关的问题中的意义，例如在神经科学中的韦伯定律的应用，以及通过仿生学在特定量子技术中的实现。我们还展示了长程相互作用的存在如何强烈影响小世界网络和幂律全连接网络中激发态的动力学。确实，由于协同屏蔽，随着连通性或相互作用范围的增加，初始激发态在网络中的扩散变得更慢，并且对初始条件高度依赖。
Complex quantum networks are powerful tools in the modeling of transport phenomena, particularly for biological systems, and enable the study of emergent phenomena in many-body quantum systems. High connectivity and long range interactions induce strong constraints on the system dynamics. Here, we study the transport properties of a quantum network described by the paradigmatic XXZ Hamiltonian, with non-trivial graph connectivity and topology, and long-range interaction. We show how long range interactions induce a memory preserving effects and strongly affect the spreading of the excitations due to cooperative shielding. We describe the memory-preserving effect in all-to-all connected regular networks with distance-independent couplings. Indeed the memory of the number of initially injected excitations is preserved over long times, being encoded in the number of frequencies present in the dynamics. Interestingly, we find that memory-preserving effects occur also in less regular graphs, such as quantum networks with either power-law node connectivity or complex, small-world type, architectures. We discuss the implications of these properties in biology-related problems, such as an application to Weber's law in neuroscience, and their implementation in specific quantum technologies via biomimicry. We also show how the presence of long range interaction strongly affect the dynamics of the excitations in small-world networks and power law all-to-all coupled networks. Indeed due to cooperative shielding as the connectivity or the range of interaction increase the initial excitation spreads more slowly among the network and becomes strongly dependent on the initial conditions.
- [58] arXiv:2503.07468 (替换) [中文pdf, pdf, html, 其他]
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标题： 多体局域化系统中的魔力动力学标题： Magic dynamics in many-body localized systems主题： 量子物理 (quant-ph) ; 无序系统与神经网络 (cond-mat.dis-nn)
非稳定性质，也称为量子魔力，量化了量子态与稳定器态之间的偏离程度，捕捉了实现量子计算优势所需的复杂性。 在本研究中，我们利用稳定器Rényi熵（SRE）研究无序多体局部化（MBL）系统中量子魔力的动力学。 借助基于$\ell$-bit模型的表观描述，我们通过分析和数值模拟证明，相互作用深刻影响魔力的扩散，导致SRE呈现幂律增长，这与遍历系统中观察到的快速饱和明显不同。 我们通过无序横向场伊辛模型的数值模拟验证了理论预测，在各种无序强度、系统尺寸和初始状态下均表现出良好的一致性。 此外，我们发现SRE与纠缠熵之间存在普遍关系，揭示了它们在MBL区域内共同的标度特性，而与无序强度和系统大小无关。 我们的结果为理解无序、相互作用和复杂性在量子多体系统中的相互作用提供了关键见解。
Nonstabilizerness, also known as quantum magic, quantifies the deviation of quantum states from stabilizer states, capturing the complexity necessary for quantum computational advantage. In this study, we investigate the dynamics of quantum magic in disordered many-body localized (MBL) systems using the stabilizer R\'enyi entropy (SRE). Leveraging a phenomenological description based on the $\ell$-bit model, we analytically and numerically demonstrate that interactions profoundly influence magic spreading, inducing a power-law growth of SRE that markedly contrasts with the rapid saturation observed in ergodic systems. We validate our theoretical predictions through numerical simulations of the disordered transverse-field Ising model, showing excellent agreement across various disorder strengths, system sizes, and initial states. Additionally, we uncover a universal relationship between SRE and entanglement entropy, revealing their common scaling in the MBL regime independent of disorder strength and system size. Our results offer critical insights into the interplay of disorder, interactions, and complexity in quantum many-body systems.
- [59] arXiv:2503.16678 (替换) [中文pdf, pdf, html, 其他]
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标题： QCPINN：用于求解偏微分方程的量子-经典物理信息神经网络标题： QCPINN: Quantum-Classical Physics-Informed Neural Networks for Solving PDEs主题： 量子物理 (quant-ph) ; 机器学习 (cs.LG)
物理信息神经网络（PINNs）已成为通过在神经架构中嵌入物理定律来求解偏微分方程（PDEs）的有前景的方法。 然而，这些经典方法通常需要大量参数才能达到合理的准确性，特别是对于复杂的PDEs。 在本文中，我们提出了一种量子-经典物理信息神经网络（QCPINN），它结合了量子和经典组件，使我们能够在显著减少参数数量的同时保持与经典PINNs相当的准确性和收敛性。 我们系统地评估了两种量子电路架构在五个基准PDE上的各种配置，以确定最优的QCPINN设计。 我们的结果表明，QCPINN实现了稳定的收敛和可比的准确性，同时所需的可训练参数仅为经典方法的约10%。 它还使对流扩散方程的相对误差$L_2$减少了40%。 这些发现展示了参数效率作为物理信息机器学习中可测量的量子优势的潜力，显著降低了模型复杂度，同时保持了解决方案的质量。 这种方法为解决PDEs相关的计算挑战提供了一个有前景的解决方案。
Physics-informed neural networks (PINNs) have emerged as promising methods for solving partial differential equations (PDEs) by embedding physical laws within neural architectures. However, these classical approaches often require a large number of parameters to achieve reasonable accuracy, particularly for complex PDEs. In this paper, we present a quantum-classical physics-informed neural network (QCPINN) that combines quantum and classical components, allowing us to solve PDEs with significantly fewer parameters while maintaining comparable accuracy and convergence to classical PINNs. We systematically evaluated two quantum circuit architectures across various configurations on five benchmark PDEs to identify optimal QCPINN designs. Our results demonstrate that the QCPINN achieves stable convergence and comparable accuracy, while requiring approximately 10\% of the trainable parameters used in classical approaches. It also results in a 40\% reduction in the relative error $L_2$ for the convection-diffusion equation. These findings demonstrate the potential of parameter efficiency as a measurable quantum advantage in physics-informed machine learning, significantly reducing model complexity while preserving solution quality. This approach presents a promising solution to the computational challenges associated with solving PDEs.
- [60] arXiv:2503.18535 (替换) [中文pdf, pdf, html, 其他]
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标题： 关于在对撞机上测试贝尔定域性标题： About testing Bell locality at colliders主题： 量子物理 (quant-ph) ; 高能物理 - 实验 (hep-ex) ; 高能物理 - 现象学 (hep-ph) ; 物理的历史与哲学 (physics.hist-ph)
对撞机使在强相互作用和弱电相互作用同时存在的情况下，能够对量子力学进行最基本层面的测试。 粒子物理自然提供了不仅由量子比特还由量子三态组成的系统示例。 对撞机上的量子层析成像使得测量纠缠和检验贝尔局域性成为可能。 我们提供了一个全面的解释，说明这是如何实现的，以及为什么它为局部隐变量模型用来逃避贝尔测试的漏洞提供了新的视角。
Colliders enable the testing of quantum mechanics at its most fundamental level, and in the presence of both strong and electroweak interactions. Particle physics naturally provides examples of systems that consist not only of qubits but also qutrits. Quantum tomography at colliders makes possible the measurement of entanglement and the testing of Bell locality. We provide a comprehensive explanation of how this is achieved and why it offers a novel perspective on the loopholes exploited by local hidden variable models to evade Bell tests.
- [61] arXiv:2503.18906 (替换) [中文pdf, pdf, html, 其他]
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标题： 向量子互联网的纠缠交换系统标题： Entanglement swapping systems toward a quantum internetSamantha I. Davis, Raju Valivarthi, Andrew Cameron, Cristian Pena, Si Xie, Lautaro Narvaez, Nikolai Lauk, Chang Li, Kelsie Taylor, Rahaf Youssef, Christina Wang, Keshav Kapoor, Boris Korzh, Neil Sinclair, Matthew Shaw, Panagiotis Spentzouris, Maria Spiropulu评论： 17页，11图主题： 量子物理 (quant-ph)
我们展示了在电信波长1536.4 nm下的时间箱量子比特之间的条件纠缠交换，即纠缠的隐形传态，保真度高达87%。 我们的系统可部署，利用模块化、现成的、光纤耦合的和电控的组件，如电光调制器。 它利用超导纳米线探测器的精确时间分辨率，这些探测器通过自定义开发的图形用户界面进行控制和读取。 交换过程通过基于特征函数的分析模型进行描述、解释和指导，该模型考虑了现实中的缺陷。 我们的系统支持量子网络协议，包括源无关的量子密钥分发，预计保密密钥速率为每筛选位约0.5比特。
We demonstrate conditional entanglement swapping, i.e. teleportation of entanglement, between time-bin qubits at the telecommunication wavelength of 1536.4 nm with high fidelity of 87\%. Our system is deployable, utilizing modular, off-the-shelf, fiber-coupled, and electrically controlled components such as electro-optic modulators. It leverages the precise timing resolution of superconducting nanowire detectors, which are controlled and read out via a custom developed graphical user interface. The swapping process is described, interpreted, and guided using characteristic function-based analytical modeling that accounts for realistic imperfections. Our system supports quantum networking protocols, including source-independent quantum key distribution, with an estimated secret key rate of approximately 0.5 bits per sifted bit.
- [62] arXiv:2503.20238 (替换) [中文pdf, pdf, html, 其他]
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标题： 物质中中微子传播的量子电路标题： Quantum circuits for simulating neutrino propagation in matter评论： 9页，8图；已发表版本期刊参考： 物理期刊 100 (2025) 085111主题： 量子物理 (quant-ph) ; 高能物理 - 现象学 (hep-ph)
量子模拟粒子现象是一个迅速发展的研究领域。 随着量子模拟器的广泛可用，给定的量子系统可以通过多种方式模拟，为实现和探索提供了灵活性。 在这里，我们对物质中的中微子传播进行量子模拟，这一现象在中微子振荡中起着关键作用。 我们提出了具有新颖门排列的量子电路，以模拟恒定和变化物质密度分布中的中微子传播。 振荡概率通过在中微子味基中编码和测量量子比特状态来确定，与理论预测表现出很好的一致性。
Quantum simulation of particle phenomena is a rapidly advancing field of research. With the widespread availability of quantum simulators, a given quantum system can be simulated in numerous ways, offering flexibility in implementation and exploration. Here, we perform quantum simulation of neutrino propagation in matter, a phenomenon that plays a crucial role in neutrino oscillations. We present quantum circuits with novel gate arrangements to simulate neutrino propagation in both constant and varying matter density profiles. The oscillation probabilities are determined by encoding and measuring the qubit states in the neutrino flavor basis, showing excellent agreement with theoretical predictions.
- [63] arXiv:2504.04624 (替换) [中文pdf, pdf, html, 其他]
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标题： 量子声景与音乐笔记标题： Notes on Quantum Soundscapes and Music评论： 31页，4张图，3个附录（包含生成量子声景和音乐作品的代码）主题： 量子物理 (quant-ph)
我们描述了对各种介观机械振子系统实验数据的听觉化研究，这些系统被冷却到接近其量子基态，以及对受各种单位旋转影响的单个量子比特测量数据的听觉化研究，这些旋转旨在测试Leggett-Garg不等式。 通过其产生的听觉化效果“聆听”数据，有助于发现可能在常规图形（即视觉）表示中难以检测的信号，对于量子比特实验来说，提供了一种补充的方法来判断数据是否违反宏观现实性，这需要一些预先的听觉训练。 所产生的声音景观和音乐也为非专家提供了一个可以轻松理解的量子领域的补充视角。
We describe our investigations involving the sonification of data from experiments involving various mesoscopic mechanical oscillator systems cooled to close to their quantum ground states, as well as the sonification of measured data from a single qubit subject to various unitary rotations designed to test the Leggett-Garg inequality. "Listening" to data via their resulting sonifications facilitates the discovery of signals that might otherwise be hard to detect in common graphic (i.e., visual) representations, and for the qubit experiment provides a complementary way to discern when the data violates macroscopic realism with some prior listening training. The resulting soundscapes and music also provide a complementary window into the quantum realm that is accessible to non-experts with open ears.
- [64] arXiv:2504.14499 (替换) [中文pdf, pdf, html, 其他]
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标题： 最大纠缠态并不总是用于单次区分单位算子有用标题： Maximally entangled states are not always useful for single shot distinguishability of unitaries主题： 量子物理 (quant-ph)
在许多情况下，作为探测器的极大纠缠态在区分量子通道的任务中比乘积态和非极大纠缠态表现更好。 我们提供了一个证明，表明对于两个幺正通道的单次区分，纠缠态和乘积态在操作上是等价的。 但我们识别出一些幺正算符对，它们可以使用非极大纠缠态完美区分，但不能用极大纠缠态区分。 当幺正算符的数量超过两个时，这种差异更加明显。 在每个维度$\geqslant 3$中，我们证明存在一类幺正算符，在极大纠缠探测器下无法区分，但使用乘积态或非极大纠缠输入却可以完美区分。 在每个维度$\geqslant 3$中还提出了一组有趣的幺正算符，其中只有非极大纠缠态可以作为成功的探测器，而乘积态和极大纠缠态则不行。
There have been many instances where the maximally entangled state as a probe acts better than the product and the non-maximally entangled states in the task of distinguishing quantum channels. We provide a proof that for single-shot discrimination of two unitary channels, entangled and product states are operationally equivalent. But we identify pairs of unitaries that are perfectly distinguishable using a non-maximally entangled state, but not with a maximally entangled one. This contrast becomes more pronounced when the number of unitaries exceeds two. In every dimension $\geqslant 3$, we show that there exists a class of unitaries that are indistinguishable under maximally entangled probes, yet perfectly distinguishable using product or non-maximally entangled inputs. Another interesting set of unitaries in every dimension $\geqslant 3$ has been presented where only non-maximally entangled state acts as the successful probe, while product states and maximally entangled states cannot.
- [65] arXiv:2504.15230 (替换) [中文pdf, pdf, html, 其他]
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标题： 近似可积性与交错里德伯阶梯中的精确复兴标题： Proximate integrability and exact revivals in staggered Rydberg ladders评论： 稿件的重新组织，更新的标题主题： 量子物理 (quant-ph) ; 统计力学 (cond-mat.stat-mech)
冷里德伯原子被囚禁在光学镊子阵列中，可以使用激光光进行操控。 我们研究了在强阻塞 regime 下，一种在正方形 ladder 几何结构中排列的里德伯原子模型中非平衡量子动力学的演化，其中失谐分布沿着较长方向交错。 当交错强度被调节时，该模型表现出一系列广泛的动力学现象，从量子多体疤痕、可积性引起的慢动力学和近似 Krylov 破裂。 此外，通过利用谱的手性特性，我们设计了弗洛凯协议，这些协议产生了类似于离散时间晶体秩序和精确弗洛凯平坦带的动力学特征。
Cold Rydberg atoms trapped in an array of optical tweezers can be manipulated using laser light. We investigate the fate of out-of-equilibrium quantum dynamics in a model of Rydberg atoms arranged in a square ladder geometry within the strong blockade regime, with a detuning profile staggered along the longer direction. As the staggering strength is tuned, the model exhibits a wide class of dynamical phenomena, ranging from quantum many-body scars, integrability-induced slow dynamics and approximate Krylov fractures. Furthermore, by leveraging the chiral nature of the spectrum, we design Floquet protocols which result in dynamical signatures reminiscent of discrete-time-crystalline order and exact Floquet-flat-bands.
- [66] arXiv:2504.18074 (替换) [中文pdf, pdf, html, 其他]
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标题： 在中性原子基态上制备Greenberger-Horne-Zeilinger态标题： Preparing Greenberger-Horne-Zeilinger state on ground levels of neutral atoms评论： 14页，7图期刊参考： 物理评论A 112，022602 (2025)主题： 量子物理 (quant-ph)
我们提出了一种在里德伯原子系统中生成格林伯格-霍恩-泽林（GHZ）态的可扩展协议，其中量子比特编码在超精细基态能级上。我们的系统以非共振驱动场为特色，而不是足够强的里德伯相互作用以实现阻塞。它能够紧密跟随时间演化过程中的所需非绝热跃迁，并通过施加依赖于跃迁且快速变化的全局相位来避免不需要的跃迁，这作为对通用量子控制的误差校正。在我们的协议中，一个$N$-量子比特的GHZ态在$N-1$步骤内制备，发现其对环境噪声和系统偏差都具有鲁棒性。因此，我们的协议为大规模纠缠提供了一条途径，这对于基于中性原子的量子信息处理和计算是必不可少的。
We propose a scalable protocol in the Rydberg atomic system to generate the Greenberger-Horne-Zeilinger (GHZ) states, where the qubits are encoded on the hyperfine ground levels. Our system is featured with off-resonant driving fields rather than strong Rydberg interaction sufficient for blockade. Closely it can follow the desired nonadiabatic passage during the time evolution and avoid the unwanted transition by imposing the passage-dependent and fast-varying global phase, that serves as an error correction to the universal quantum control. In our protocol, an $N$-qubit GHZ state is prepared in $N-1$ steps, which is found to be robust against both environmental noise and systematic deviation. Our protocol therefore provides an avenue toward large-scale entanglement, which is essential for quantum information processing and computation based on neutral atoms.
- [67] arXiv:2504.19613 (替换) [中文pdf, pdf, html, 其他]
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标题： 光量子网络的自动配置协议标题： Automatic Configuration Protocols for Optical Quantum Networks评论： 11页，7图主题： 量子物理 (quant-ph) ; 网络与互联网架构 (cs.NI)
在量子网络能够扩展到实际规模之前，有许多部署和配置任务必须实现自动化。 目前，量子网络测试平台主要通过手动配置：网络节点由自由空间和光纤的组合构建，然后连接到共享的单光子探测器、时间到数字转换器和光开关。 这些连接的信息必须手动跟踪；标签错误可能导致实验失败和漫长的调试过程。 在本文中，我们提出了协议和算法来自动化这两种手动流程。 首先，我们解决自动识别量子网络节点与时间到数字转换器之间连接的问题。 然后，我们转向更复杂的挑战，即识别连接到量子网络光开关的节点。 这些协议的实现将有助于推动量子网络所需其他协议的发展，例如网络拓扑发现、链路质量监控、资源命名和路由。 我们希望本文能作为近期实现的路线图。
Before quantum networks can scale up to practical sizes, there are many deployment and configuration tasks that must be automated. Currently, quantum networking testbeds are largely manually configured: network nodes are constructed out of a combination of free-space and fiber optics before being connected to shared single-photon detectors, time-to-digital converters, and optical switches. Information about these connections must be tracked manually; mislabeling may result in experimental failure and protracted debugging sessions. In this paper, we propose protocols and algorithms to automate two such manual processes. First, we address the problem of automatically identifying connections between quantum network nodes and time-to-digital converters. Then, we turn to the more complex challenge of identifying the nodes attached to a quantum network's optical switches. Implementation of these protocols will help enable the development of other protocols necessary for quantum networks, such as network topology discovery, link quality monitoring, resource naming, and routing. We intend for this paper to serve as a roadmap for near-term implementation.
- [68] arXiv:2505.02297 (替换) [中文pdf, pdf, html, 其他]
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标题： 通过对称测量估计量子态的施密特数标题： Estimating the Schmidt numbers of quantum states via symmetric measurements期刊参考： 物理学年鉴 2025，e00259主题： 量子物理 (quant-ph)
施密特数量化了量子态的纠缠程度。 具有高施密特数的量子态在各种量子信息处理任务中相比具有低施密特数的量子态具有更大的优势。 我们基于从对称测量中获得的相关矩阵的迹范数推导出一个施密特数准则。 我们通过详细示例展示了我们的结果比现有的施密特数准则更有效且更优越。
The Schmidt numbers quantify the entanglement degree of quantum states. Quantum states with high Schmidt numbers provide a larger advantage in various quantum information processing tasks compared to quantum states with low Schmidt numbers. We derive a Schmidt number criterion based on the trace norm of the correlation matrix obtained from symmetric measurements. We show that our result is more effective than and superior to existing Schmidt number criteria by detailed examples.
- [69] arXiv:2505.21192 (替换) [中文pdf, pdf, html, 其他]
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标题： 关于能量本征值对应黎曼零点的哈密顿量标题： On the Hamiltonian with Energy Levels Corresponding to Riemann Zeros评论： 欢迎提出评论主题： 量子物理 (quant-ph) ; 数学物理 (math-ph)
一个具有本征能量$E_n = \rho_n(1-\rho_n) $的哈密顿量已被构造，其中$\rho_n $表示黎曼zeta函数的第$n$个非平凡零点。 为了构造这样的哈密顿量，我们推广了Berry-Keating的范式，并通过模形式将数论信息编码到哈密顿量中。 尽管我们的构造并未解决Hilbert-Pólya猜想——因为对应于$E_n$的本征态是\emph{不}可归一化状态——但它为黎曼假设(RH)提供了新颖的物理视角。 特别是，我们提出了RH的一个物理陈述，这可能成为其证明的潜在途径。
A Hamiltonian with eigenenergies $E_n = \rho_n(1-\rho_n) $ has been constructed, where $\rho_n $ denotes the $n$-th non-trivial zero of the Riemann zeta function. To construct such a Hamiltonian, we generalize the Berry-Keating's paradigm and encode number-theoretic information into the Hamiltonian through modular forms. Even though our construction does not resolve the Hilbert-P\'olya conjecture -- since the eigenstates corresponding to $E_n$ are \emph{not} normalizable states -- it offers a novel physical perspective on the Riemann Hypothesis(RH). Especially, we proposed a physical statement of RH, which may serve as a potential pathway toward its proof.
- [70] arXiv:2506.23379 (替换) [中文pdf, pdf, 其他]
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标题： 量子计算架构与硬件——逐步指南——第二卷标题： Quantum Computing Architecture and Hardware for Engineers -- Step by Step -- Volume II主题： 量子物理 (quant-ph)
在出版了我的书籍《量子计算架构与硬件工程师：逐步指南》[1]（现在我称之为第一卷）之后，其中涵盖了自旋量子位和超导量子位量子计算机，我决定继续撰写第二卷，以涵盖囚禁离子量子位量子计算机，这也在我的EE274课程中教授过。 我遵循第一卷的相同结构，通过讨论物理、数学以及它们如何满足五个DiVincenzo标准来连接激光脉冲和电子设备。 我认为将第二卷发布在arXiv上是个好主意，这样更多人可以免费阅读，并且我可以继续更新内容。 截至2025年7月，我已经完成了囚禁离子量子计算机部分。 未来，我计划以逐步的方式撰写更多关键主题，以帮助那些没有接受过严格物理训练的工程师进入量子计算领域。
After publishing my book "Quantum Computing Architecture and Hardware for Engineers: Step by Step" [1] (now I call it Volume I), in which spin qubit and superconducting qubit quantum computers were covered, I decided to continue to write the second volume to cover the trapped ion qubit quantum computer, which was also taught in my EE274 class. I follow the same structure as in Volume I by discussing the physics, mathematics, and their connection to laser pulses and electronics based on how they fulfill the five DiVincenzo's criteria. I also think it would be a good idea to share the second volume on arXiv so that more people can read it for free, and I can continue to update the contents. As of July 2025, I have finished the trapped ion quantum computer part. In the future, I plan to write more critical topics in a step-by-step manner to bridge engineers who did not receive rigorous training in Physics to the quantum computing world.
- [71] arXiv:2507.03642 (替换) [中文pdf, pdf, html, 其他]
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标题： 使用非线性耦合的高功率读出单子量子比特标题： High-power readout of a transmon qubit using a nonlinear couplingCyril Mori, Vladimir Milchakov, Francesca D'Esposito, Lucas Ruela, Shelender Kumar, Vishnu Narayanan Suresh, Waël Ardati, Dorian Nicolas, Giulio Cappelli, Arpit Ranadive, Gwenael Le Gal, Martina Esposito, Quentin Ficheux, Nicolas Roch, Tomás Ramos, Olivier Buisson评论： 17页，8图主题： 量子物理 (quant-ph) ; 中尺度与纳米尺度物理 (cond-mat.mes-hall)
超导量子比特领域不断演进，出现了新的电路设计。然而，在量子比特读出方面，简单的横向线性耦合仍然占主导地位。这种标准的读出方案存在显著缺点：除了普尔塞效应外，它还受到读出模式中最大光子数的限制，这限制了信噪比（SNR）和读出的量子非破坏性（QND）特性。在此，我们通过在transmon量子比特与其读出模式之间工程化非线性耦合来探索高功率 regime。我们的方法建立在Dassonneville等人之前的工作基础上[Physical Review X 10, 011045 (2020)]，他们在transmon分子中使用非微扰交叉-Kerr耦合进行量子比特读出。我们利用参数放大器实现了99.21%的读出保真度，使用了89个光子。在这一较高的光子数下，QND特性仍保持在96.7%。即使达到300个光子，QND特性仅减少几个百分点。定性上可以通过推导与非线性耦合相关的临界光子数来解释，对于我们样本的参数，理论值为$\bar{n}_r^\text{crit} = 377$个光子。这些结果突显了transmon分子在高功率 regime 中的出色性能，确立了其作为高保真度量子比特读出的有吸引力的平台。
The field of superconducting qubits is constantly evolving with new circuit designs. However, when it comes to qubit readout, the use of simple transverse linear coupling remains overwhelmingly prevalent. This standard readout scheme has significant drawbacks: in addition to the Purcell effect, it suffers from a limitation on the maximal number of photons in the readout mode, which restricts the signal-to-noise ratio (SNR) and the Quantum Non-Demolition (QND) nature of the readout. Here, we explore the high-power regime by engineering a nonlinear coupling between a transmon qubit and its readout mode. Our approach builds upon previous work by Dassonneville et al. [Physical Review X 10, 011045 (2020)], on qubit readout with a non-perturbative cross-Kerr coupling in a transmon molecule. We demonstrate a readout fidelity of 99.21% with 89 photons utilizing a parametric amplifier. At this elevated photon number, the QND nature remains high at 96.7%. Even with up to 300 photons, the QNDness is only reduced by a few percent. This is qualitatively explained by deriving a critical number of photons associated with the nonlinear coupling, yielding a theoretical value of $\bar{n}_r^\text{crit} = 377$ photons for our sample's parameters. These results highlight the promising performance of the transmon molecule in the high-power regime, establishing it as a compelling platform for high-fidelity qubit readout.
- [72] arXiv:2507.11766 (替换) [中文pdf, pdf, html, 其他]
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标题： 戈林尼-科萨克斯基-苏达良-林德布拉德生成定理，以及对非平稳演化的推广标题： The Gorini-Kossakowski-Sudarshan-Lindblad generation theorem,and a generalization to non-stationary evolutions评论： 16页。后续章节中有大量修改，包括对晦涩段落的重写、新的术语和符号，以及关于连续选择Lindblad分解的新章节主题： 量子物理 (quant-ph) ; 数学物理 (math-ph)
The Lindblad equation embodies a fundamental paradigm of the quantum theory of open systems, and the Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) generation theorem says precisely which superoperators can appear on its right-hand side. These are the generators of completely positive trace-preserving (or nonincreasing) semigroups. A complete exposition of this theorem is given. The finite-dimensional case is handled using a form of Jamio\l{}kowski transform. The treatment requires no previous knowledge of complete positivity and obtains the Choi-Kraus presentation along the way. The (separable) infinite-dimensional case is handled by means of a sequence of finite-dimensional approximations, using the finite-dimensional case as a crucial tool. An extension to time-dependent generator is given.The condition for CP evolution is just that for semigroups applied at each instant, and the Lindblad decomposition can be chosen continuous in time.
The Lindblad equation embodies a fundamental paradigm of the quantum theory of open systems, and the Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) generation theorem says precisely which superoperators can appear on its right-hand side. These are the generators of completely positive trace-preserving (or nonincreasing) semigroups. A complete exposition of this theorem is given. The finite-dimensional case is handled using a form of Jamio\l{}kowski transform. The treatment requires no previous knowledge of complete positivity and obtains the Choi-Kraus presentation along the way. The (separable) infinite-dimensional case is handled by means of a sequence of finite-dimensional approximations, using the finite-dimensional case as a crucial tool. An extension to time-dependent generator is given.The condition for CP evolution is just that for semigroups applied at each instant, and the Lindblad decomposition can be chosen continuous in time.
- [73] arXiv:2507.13161 (替换) [中文pdf, pdf, html, 其他]
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标题： 机械压缩态量子比特：面向量子弱力传感标题： Mechanical Squeezed-Fock Qubit: Towards Quantum Weak-Force Sensing评论： 7+10页，3+2图主题： 量子物理 (quant-ph)
机械量子比特相较于其他量子比特平台具有独特的优势，主要体现在相干时间和增强传感应用的可能性方面，但其潜力受到纳米机械谐振器固有的弱非线性和谐波性较小的限制。 我们提出通过使用参数驱动的非线性机械振荡器中的声子压缩数态来克服这一缺点。 我们发现，在双声子驱动下，压缩数态成为Kerr非线性机械振荡器的本征态，其能量谱具有指数级增强且可调的非谐性，从而使向更高能态的跃迁被指数级抑制。 这使我们能够在驱动的机械振荡器的基态和第一激发压缩数态中编码机械量子比特。 这种机械量子比特被称为机械压缩数态量子比特。 我们还表明，我们的机械量子比特可以作为弱力的量子传感器，其灵敏度至少比传统机械量子比特提高一个数量级。 所提出的机械压缩数态量子比特为量子传感和信息处理提供了一个强大的量子声子平台。
Mechanical qubits offer unique advantages over other qubit platforms, primarily in terms of coherence time and possibilities for enhanced sensing applications, but their potential is constrained by the inherently weak nonlinearities and small anharmonicity of nanomechanical resonators. We propose to overcome this shortcoming by using squeezed Fock states of phonons in a parametrically driven nonlinear mechanical oscillator. We find that, under two-phonon driving, squeezed Fock states become eigenstates of a Kerr-nonlinear mechanical oscillator, featuring an energy spectrum with exponentially enhanced and tunable anharmonicity, such that the transitions to higher energy states are exponentially suppressed. This enables us to encode the mechanical qubit within the ground and first excited squeezed Fock states of the driven mechanical oscillator. This kind of mechanical qubit is termed mechanical squeezed-Fock qubit. We also show that our mechanical qubit can serve as a quantum sensor for weak forces, with its resulting sensitivity increased by at least one order of magnitude over that of traditional mechanical qubits. The proposed mechanical squeezed-Fock qubit provides a powerful quantum phonon platform for quantum sensing and information processing.
- [74] arXiv:2507.14892 (替换) [中文pdf, pdf, html, 其他]
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标题： 异常点动力学标题： Exceptional-Point Dynamics评论： 7页，3图用于正文；16页，5图用于补充材料主题： 量子物理 (quant-ph)
异常点（EPs）在非厄米（NH）系统中起着关键作用，驱动独特的动态现象并有望带来创新应用。 然而，由于缺陷非厄米哈密顿量的双正交本征空间不完整，EP处的NH动力学仍然模糊，因此通常被避免。 在本文中，我们通过使用所有可用的广义本征态，系统地建立了EP处的伪完备关系，其中处理了包含简并情况的单个和多个任意阶EP，以揭示EP动力学。 我们发现，根据EP阶数和初始条件，EP动力学由合并本征态或其叠加的\emph{随时间增长的多项式增长}所表征，这将在伪厄米性（PH）保护的实谱下主导长期演化，或者也可以变为幺正的。 我们进一步引入两种符合PH的非厄米模型来演示这些EP动力学并探索其应用。 这项工作完成了对NH物理的动力学研究，为EP处的非幺正演化提供了有价值的见解，并为进一步工程和利用与EP相关的器件和技术奠定了基础。
Exceptional points (EPs) play a vital role in non-Hermitian (NH) systems, driving unique dynamical phenomena and promising innovative applications. However, the NH dynamics at EPs remains obscure due to the incomplete biorthogonal eigenspaces of defective NH Hamiltonians and thus is often avoided. In this manuscript, we systematically establish pseudo-completeness relations at EPs by employing all available generalized eigenstates, where both single and multiple arbitrary-order EPs embracing degenerate scenarios are addressed, to unveil EP dynamics. We reveal that depending on EP order and initial conditions, the EP dynamics is characterized by a \emph{polynomial growth over time} of coalescing eigenstates or their superposition, which will dominate long-term evolution despite real spectra protected by pseudo-Hermiticity (PH), or can also become unitary. We further introduce two PH-compliant NH models to demonstrate these EP dynamics and explore their applications. This work completes the dynamical investigation of NH physics, offers valuable insights into the nonunitary evolution at EPs, and further lays the foundation for engineering and exploiting EP-related devices and technologies.
- [75] arXiv:2507.19430 (替换) [中文pdf, pdf, html, 其他]
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标题： 方向性编码：一种在六边形和方形网格连接硬件上的新型量子LDPC编码标题： Directional Codes: a new family of quantum LDPC codes on hexagonal- and square-grid connectivity hardware评论： 共38页，正文26页，附录12页，24幅图主题： 量子物理 (quant-ph)
大规模量子计算需要量子纠错（QEC）来保护量子信息免受噪声影响。 目前，超导硬件是实现容错的有希望的候选者，因为其门操作速度快且可扩展性可行。 然而，它通常受限于二维最近邻连接，这被认为无法容纳高率量子低密度奇偶校验（qLDPC）码，这些码有望大大减少编码逻辑量子比特所需的物理量子比特数量。 在本文中，我们构建了一种新的qLDPC码族，我们称之为“方向码”，其性能优于旋转平面码（RPC），同时自然满足广泛采用的正方形网格的连接要求，甚至某些更稀疏的六边形网格。 关键思想是利用iSWAP门——超导量子比特的自然原生门——来构建测量这些qLDPC码的稳定子的电路，而无需任何长程连接或增加连接度。 我们使用一个常见的超导启发式电路级泡利噪声模型，对编码四个、六个和十二个逻辑量子比特的方向码进行数值评估。 我们还将它们与RPC和双变量自行车（BB）码进行比较，目前这是两种最流行的量子LDPC码族。 作为具体例子，方向码在物理错误率$p=10^{-3}$的情况下，仅使用距离高达$10$的$18.75-45\%$的物理量子比特，就能达到与RPC相近的逻辑错误概率。 我们的发现代表了QEC码设计的一个突破，表明复杂的长程、高连接度硬件可能不是低开销容错量子计算所必需的。
Utility-scale quantum computing requires quantum error correction (QEC) to protect quantum information against noise. Currently, superconducting hardware is a promising candidate for achieving fault tolerance due to its fast gate times and feasible scalability. However, it is often restricted to two-dimensional nearest-neighbour connectivity, which is thought to be incapable of accommodating high-rate quantum low-density parity-check (qLDPC) codes that promise to greatly reduce the number of physical qubits needed to encode logical qubits. In this paper we construct a new family of qLDPC codes, which we call ``Directional Codes'', that outperforms the rotated planar code (RPC) while naturally meeting the connectivity requirements of the widely adopted square-grid, and some even the sparser hexagonal-grid. The key idea is to utilise the iSWAP gate -- a natural native gate for superconducting qubits -- to construct circuits that measure the stabilisers of these qLDPC codes without the need for any long-range connections or an increased degree of connectivity. We numerically evaluate the performance of directional codes, encoding four, six and twelve logical qubits, using a common superconducting-inspired circuit-level Pauli noise model. We also compare them to the RPC and to the bivariate bicycle (BB) codes, currently the two most popular quantum LDPC code families. As a concrete example, directional codes outperform the RPC by achieving approximately the same logical error probability at physical error rate $p=10^{-3}$ using only $18.75-45\%$ of the physical qubits at distance up to $10$. Our discovery represents a breakthrough in QEC code design that suggests complex long-range, high-connectivity hardware may not be necessary for low-overhead fault-tolerant quantum computation.
- [76] arXiv:2508.01397 (替换) [中文pdf, pdf, html, 其他]
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标题： 通过有限测量时间下压缩输入光增强重力诱导的纠缠标题： Enhanced Gravity-Induced Entanglement via Squeezed Input Light under Finite Measurement Time评论： 13页，5图主题： 量子物理 (quant-ph) ; 广义相对论与量子宇宙学 (gr-qc)
我们研究了在傅里叶域分析中使用压缩输入光生成引力诱导纠缠（GIE）的优势。 基于文献[1]的发现，该研究展示了在量子控制下检测GIE在光机械系统中的可行性，我们进一步证明压缩输入光可以减少机械条件态中的光学噪声并增强GIE。 此外，我们估计了在有限测量时间内使用傅里叶变换测量GIE时的系统误差和统计误差。 基于使用信号噪声比（SNR）进行的误差估计，在GIE检测中，当使用压缩输入光时，需要总测量时间为10^6秒才能达到SNR=1，而无需压缩输入光时则需要10^{6.8}秒。 这一结果突显了光机械系统的有效性以及压缩输入光在增强GIE可检测性中的关键作用。
We investigate the advantage of using squeezed input light for generating gravity-induced entanglement (GIE) through Fourier-domain analysis. Based on the findings of [1], which demonstrated the feasibility of detecting GIE in optomechanical systems under quantum control, we further demonstrate that squeezed input light can reduce the optical noise in the mechanical conditional state and enhance GIE. Furthermore, we estimate the systematic and statistical errors in the measurement of GIE using the Fourier transformation over a finite measurement time. Based on the error estimations using the signal-to-noise ratio (SNR) in GIE detection, we find that a total measurement time of 10^6 s is required to achieve SNR=1 when using squeezed input light, whereas 10^{6.8} s is needed without squeezed input light. This result highlights the effectiveness of optomechanical systems and the critical role of squeezed input light in enhancing the detectability of GIE.
- [77] arXiv:2308.01514 (替换) [中文pdf, pdf, html, 其他]
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标题： 具有布罗迪间距分布的2 X 2相关随机矩阵模型类标题： A class of 2 X 2 correlated random-matrix models with Brody spacing distribution评论： 期刊接受的稿件（见下面的期刊参考文献）期刊参考： 物理学年鉴 480, 170080 (2025)主题： 数学物理 (math-ph) ; 混沌动力学 (nlin.CD) ; 量子物理 (quant-ph)
引入了一类2x2随机矩阵模型，其中Brody分布是精确的本征值间距分布。 矩阵元素由受约束的有限和组成，该有限和是指数随机变量的不同幂次，这些幂次取决于Brody参数。 此处引入的随机矩阵与高斯正交系综（GOE）的矩阵有三个重要不同之处：矩阵元素不是独立同分布（即非IID）的，也不是高斯分布的，并且矩阵不一定是实数和/或对称的。 前两个特性来自于放弃经典的独立性假设，第三个特性则来自于在GOE构造中放弃量子力学条件。 特别是，本类模型中的厄米特性条件是本征值为实数的充分但非必要条件，并未被施加。 因此，具有实数或复数本征值的复数非厄米特2x2随机矩阵也可能具有介于泊松类和Wigner类之间的间距分布。 提供了不同类型随机矩阵的数值示例，包括具有实数或共轭复数本征值的复数对称矩阵。 讨论了各种推广和扩展，包括一种简单的修改，可以实现其他本征值间距统计类之间的交叉过渡。 作为新示例，介绍了半泊松和Ginibre间距统计之间的交叉过渡情况。
A class of 2x2 random-matrix models is introduced for which the Brody distribution is the exact eigenvalue spacing distribution. The matrix elements consist of constrained finite sums of an exponential random variable raised to various powers that depend on the Brody parameter. The random matrices introduced here differ from those of the Gaussian Orthogonal Ensemble (GOE) in three important ways: the matrix elements are not independent and identically distributed (i.e., not IID) nor Gaussian-distributed, and the matrices are not necessarily real and/or symmetric. The first two features arise from dropping the classical independence assumption, and the third feature stems from dropping the quantum-mechanical conditions imposed in the construction of the GOE. In particular, the hermiticity condition, which in the present class of models, is a sufficient but not necessary condition for the eigenvalues to be real, is not imposed. Consequently, complex non-Hermitian 2x2 random matrices with real or complex eigenvalues can also have spacing distributions that are intermediate between those of the Poisson and Wigner classes. Numerical examples are provided for different types of random matrices, including complex-symmetric matrices with real or complex-conjugate eigenvalues. Various generalizations and extensions are discussed including a simple modification that effectuates cross-over transitions between other classes of eigenvalue spacing statistics. The case of a cross-over transition between semi-Poisson and Ginibre spacing statistics is presented as a novel example.
- [78] arXiv:2312.13282 (替换) [中文pdf, pdf, html, 其他]
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标题： 估计Trotter近似误差以优化哈密顿量分割以降低特征值误差标题： Estimating Trotter Approximation Errors to Optimize Hamiltonian Partitioning for Lower Eigenvalue Errors评论： 22页，1图，计算重新进行以针对二阶Trotter近似误差主题： 化学物理 (physics.chem-ph) ; 量子物理 (quant-ph)
将Trotter近似与量子相位估计算法结合，可以在量子计算机上提取多体哈密顿量的本征能量。 提出了几种方法，基于估计精确演化算子和近似演化算器之间的范数来评估这种近似的质量。 在这里，我们探讨了不同的误差估计量如何与由于Trotter近似导致的基态能量的真实误差相关。 对于一组小分子，我们计算了由于二阶Trotter近似导致的基态电子能量的精确误差。 将这些误差与之前使用的上界进行比较，显示在各种哈密顿量划分下相关性小于0.4。 另一方面，基于微扰理论，至时间步长的二阶构建Trotter近似误差估计，可以提供与精确Trotter近似误差具有非常好相关性的估计。 这些发现突显了基于范数的估计在预测基于Trotter的本征值估计性能方面的不忠实性，并强调了需要替代估计量。 开发的微扰估计可用于实际的时间步长和哈密顿量划分选择协议，这对于准确评估量子资源是必要的。
Trotter approximation in conjunction with Quantum Phase Estimation can be used to extract eigen-energies of a many-body Hamiltonian on a quantum computer. There were several ways proposed to assess the quality of this approximation based on estimating the norm of the difference between the exact and approximate evolution operators. Here, we explore how different error estimators correlate with the true error in the ground state energy due to Trotter approximation. For a set of small molecules we calculate these exact error in ground-state electronic energies due to the second-order Trotter approximation. Comparison of these errors with previously used upper bounds show correlation less than 0.4 across various Hamiltonian partitionings. On the other and, building the Trotter approximation error estimation based on perturbation theory up to a second order in the time-step for eigenvalues provides estimates with very good correlations with the exact Trotter approximation errors. These findings highlight the non-faithful character of norm-based estimations for prediction of a Trotter-based eigenvalue estimation performance and the need of alternative estimators. The developed perturbative estimates can be used for practical time-step and Hamiltonian partitioning selection protocols, which are needed for an accurate assessment of quantum resources.
- [79] arXiv:2408.10194 (替换) [中文pdf, pdf, html, 其他]
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标题： 克利洛夫复杂性作为混沌的探测器标题： Krylov Complexity as a Probe for Chaos评论： 11页，5图，v2：增加了参考文献和解释，修正了拼写错误，v3：小幅改进，与发表版本一致期刊参考： 欧洲物理杂志C 85, 749 (2025)主题： 高能物理 - 理论 (hep-th) ; 量子物理 (quant-ph)
在本工作中，我们详细探讨了Krylov复杂度的时间演化。我们通过分析计算证明，在有限多体系统中，斜坡和平台是Krylov复杂度的两个普遍特征，而复杂度饱和的方式揭示了系统的混沌性质。特别是，我们表明趋向饱和的动力学过程可以精确地区分混沌系统和可积系统。对于混沌模型，复杂度的饱和值在有限的饱和时间达到其无限时间平均值。在这种情况下，根据初始状态的不同，它可能在饱和前表现出一个峰值。相反，在可积模型中，复杂度从下方以更长的时间尺度接近无限时间平均值。我们通过特定自旋模型的数值结果确认了这一区别。
In this work, we explore in detail, the time evolution of Krylov complexity. We demonstrate, through analytical computations, that in finite many-body systems, while ramp and plateau are two generic features of Krylov complexity, the manner in which complexity saturates reveals the chaotic nature of the system. In particular, we show that the dynamics towards saturation precisely distinguish between chaotic and integrable systems. For chaotic models, the saturation value of complexity reaches its infinite time average at a finite saturation time. In this case, depending on the initial state, it may also exhibit a peak before saturation. In contrast, in integrable models, complexity approaches the infinite time average value from below at a much longer timescale. We confirm this distinction using numerical results for specific spin models.
- [80] arXiv:2409.01386 (替换) [中文pdf, pdf, html, 其他]
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标题： 量子发射器的亚波长阵列：非线性进入弱驱动区域，并导致相关的亚辐射态标题： Subwavelength arrays of quantum emitters: nonlinearities enter the weak-drive regime, and lead to correlated subradiant states评论： 14页，5图。v2的主要更新：v1在技术上仍然正确，但对结果的解释和讨论已大幅改进主题： 量子气体 (cond-mat.quant-gas) ; 量子物理 (quant-ph)
量子发射器阵列已成为重要的平台，其中可以实现并精确控制强光-物质相互作用。 在亚波长区域，它们表现出一系列亚辐射本征态，这些本征态可以容纳新的量子多体态，并且在多个应用中具有前景。 然而，由于其亚辐射特性，在弱远场驱动下它们的激发受到阻碍。 因此，弱驱动 regime 被广泛认为是线性 regime，可以用经典方程很好地描述。 在本工作中，我们发现，出人意料的是，对于常规几何结构，弱驱动 regime 实际上是强非线性的，这是由于高阶、共振和动量守恒过程对激发亚辐射态的重要贡献。 通过动力学平均场理论（DMFT），我们表明这些过程导致了相互作用的亚辐射激发对的稳态，具有双模压缩和长程特性的量子关联，实现了新型强关联的驱动-耗散态。 这些发现对非线性光学和量子计量学具有潜在影响。
Quantum emitter arrays have emerged as important platforms in which strong light-matter interactions can be achieved and precisely controlled. In subwavelength regimes, they are characterised by a manifold of subradiant eigenstates, which can host novel quantum many-body states and are promising for several applications. Nevertheless, their excitation under a weak far-field driving is prevented by their subradiant nature. Consequently, the weak-drive regime has been widely regarded as a linear regime, well described by classical equations. In this work, we find that, suprisingly, the weak-drive regime is instead strongly non-linear for regular geometries, due to the important contribution of higher-order, resonant and momentum-conserving processes exciting subradiant states. Using a Dynamical Mean-Field Theory (DMFT) we show that these processes lead to a steady state of interacting subradiant excitation pairs, with quantum correlations of two-mode squeezing and long-range character, realising a novel strongly-correlated driven-dissipative state. These findings have potential impact for non-linear optics and quantum metrology.
- [81] arXiv:2411.19658 (替换) [中文pdf, pdf, html, 其他]
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标题： 低于阈值非顺序双电离与线性偏振双色场 I：对称性和主导性标题： Below threshold nonsequential double ionization with linearly polarized two-color fields I: symmetry and dominance评论： 26页（包括附录和参考文献）和12张图；此版本已被接受发表于《物理评论A》。修改后的版本在结构上有一些微小调整，部分结果被移到了附录中。主题： 原子物理 (physics.atom-ph) ; 量子物理 (quant-ph)
我们研究用线性偏振双色场引起的非顺序双电离，重点研究再碰撞激发随后电离（RESI）机制。 使用强场近似，我们评估场的对称性如何影响主要事件。 此外，我们表明，通过调节场参数，如场频率和两个驱动波之间的相对相位，可以影响关联的电子动量分布。 线性偏振双色场的特定特征是，第二个电子的动量分布不再以零动量为中心，并且每个半周期可能有多个电离事件。 这可以用来将RESI分布限制在特定的动量区域，并确定使事件占优的参数层次。
We investigate laser-induced nonsequential double ionization with linearly polarized bichromatic fields, focusing on the recollision-excitation with subsequent ionization (RESI) mechanism. Using the strong-field approximation, we assess how the symmetries of the field influence the dominant events. Furthermore, we show that, by manipulating the field parameters such as the field frequencies and relative phase between the two driving waves, one can influence the correlated electron-momentum distributions. Specific features of a linearly polarized bichromatic field are that the momentum distributions of the second electron are no longer centered around vanishing momenta and that there may be more than one ionization event per half cycle. This can be used to confine the RESI distributions to specific momentum regions and to determine a hierarchy of parameters that make an event dominant.
- [82] arXiv:2501.10691 (替换) [中文pdf, pdf, html, 其他]
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标题： 全息量子纠缠的线程实现标题： The thread embodiment of holographic quantum entanglement评论： 49页，14图主题： 高能物理 - 理论 (hep-th) ; 量子物理 (quant-ph)
本文系统地发展了表征全息对偶纠缠结构的纠缠线概念。 这一框架背后有一种简单的哲学思想：全息量子纠缠可以用类似线状物体的图像来可视化。 受张量网络模型可以变形为具有流量守恒特性的量子电路形式这一事实的启发，我们抽象出了纠缠线的概念。 这些纠缠线可以被理解为全息量子电路中预先设定的导线集合，我们提出它们表征全息量子纠缠的底层部分有序结构。 结合纠缠线和运动空间的概念，提供了全息复杂性的一种优雅电路解释。 我们还澄清了纠缠线与之前提出的比特线概念之间的联系和区别。
This paper systematically develops the concept of entanglement threads that characterize the entanglement structure of holographic duality. Behind this framework lies a simple philosophy: holographic quantum entanglement can be visualized using thread-like objects. Inspired by the fact that tensor network models can be deformed into a quantum circuit form with flow-conserving features, we abstract the concept of entanglement threads. These entanglement threads can be understood as a pre-set ensemble of wires in a holographic quantum circuit, and we propose that they characterize the underlying partially ordered structure of holographic quantum entanglement. Combining the concepts of entanglement threads and kinematic space, a elegant circuit interpretation for the holographic complexity is provided. We also clarify the connection and distinction between entanglement threads and the previously proposed concept of bit threads.
- [83] arXiv:2503.02497 (替换) [中文pdf, pdf, html, 其他]
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标题： PennyLang：以新型PennyLane中心数据集为特色的基于LLM的量子代码生成开创性研究标题： PennyLang: Pioneering LLM-Based Quantum Code Generation with a Novel PennyLane-Centric DatasetAbdul Basit, Nouhaila Innan, Muhammad Haider Asif, Minghao Shao, Muhammad Kashif, Alberto Marchisio, Muhammad Shafique评论： 8页，6图，7表主题： 软件工程 (cs.SE) ; 人工智能 (cs.AI) ; 量子物理 (quant-ph)
大型语言模型（LLMs）在代码生成、自然语言理解和领域特定推理方面具有强大的能力。 它们在量子软件开发中的应用仍然有限，部分原因是缺乏高质量的数据集用于LLM训练以及作为可靠的知识来源。 为了弥补这一差距，我们引入了PennyLang，这是一个现成的高质量数据集，包含3,347个与PennyLane相关的量子代码样本及其上下文描述，这些样本来自教科书、官方文档和开源仓库。 我们的贡献有三个方面： (1) 创建并开源了PennyLang，这是一个专为使用PennyLane进行量子编程设计的数据集；(2) 一种自动化量子代码数据集构建框架，系统化地整理、标注和格式化以最大化下游LLM的可用性；以及(3) 在多个开源模型上对数据集的基准评估，包括消融研究，所有研究均在检索增强生成（RAG）管道中进行。 使用PennyLang与RAG显著提高了性能：例如，Qwen 7B的成功率从无检索时的8.7%提升到全上下文增强时的41.7%，而LLaMa 4则从78.8%提升到84.8%，同时减少了幻觉并增强了量子代码的正确性。 超越专注于Qiskit的研究，我们将基于LLM的工具和可重复的方法带入PennyLane，以推动AI辅助的量子开发。
Large Language Models (LLMs) offer powerful capabilities in code generation, natural language understanding, and domain-specific reasoning. Their application to quantum software development remains limited, in part because of the lack of high-quality datasets both for LLM training and as dependable knowledge sources. To bridge this gap, we introduce PennyLang, an off-the-shelf, high-quality dataset of 3,347 PennyLane-specific quantum code samples with contextual descriptions, curated from textbooks, official documentation, and open-source repositories. Our contributions are threefold: (1) the creation and open-source release of PennyLang, a purpose-built dataset for quantum programming with PennyLane; (2) a framework for automated quantum code dataset construction that systematizes curation, annotation, and formatting to maximize downstream LLM usability; and (3) a baseline evaluation of the dataset across multiple open-source models, including ablation studies, all conducted within a retrieval-augmented generation (RAG) pipeline. Using PennyLang with RAG substantially improves performance: for example, Qwen 7B's success rate rises from 8.7% without retrieval to 41.7% with full-context augmentation, and LLaMa 4 improves from 78.8% to 84.8%, while also reducing hallucinations and enhancing quantum code correctness. Moving beyond Qiskit-focused studies, we bring LLM-based tools and reproducible methods to PennyLane for advancing AI-assisted quantum development.
- [84] arXiv:2504.03005 (替换) [中文pdf, pdf, html, 其他]
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标题： 噪声影响的动力学量子相变标题： Noise-Affected Dynamical Quantum Phase Transitions评论： 完全重写的版本，其中同时考虑了混合态的广义Loschmidt回波以及对各个噪声实现的返回率的平均值主题： 统计力学 (cond-mat.stat-mech) ; 量子物理 (quant-ph)
我们研究了不相关噪声对费米子两带模型在跨临界点的量子跃迁中的动态量子相变（DQPTs）的影响。 我们考虑了一个广义的Loschmidt回波，用于噪声平均的密度矩阵$\bar\rho$，这通常是一个混合态，以及对于每个噪声实现计算的纯态Loschmidt回波，并在相应的返回速率上进行平均。 $\bar\rho$可以从主方程中得到，我们证明对于两带模型，噪声会破坏其相干性，这通常会将$\bar\rho$带向完全混合态，这是一个吸引子固定点。 因此，对于有限噪声，DQPTs始终被平滑。 另一方面，对于单个噪声实现，我们发现，在某些条件下，DQPTs始终存在，而不论噪声水平如何。 这导致在平均返回速率中出现显著的稳定但略有展宽的DQPT类似特征。 我们通过考虑一个有噪声的跃迁以及最终哈密顿量的能量水平中的噪声来说明XY模型的结果。
We investigate the effects of uncorrelated noise on dynamical quantum phase transitions (DQPTs) in fermionic two-band models following a quantum ramp across critical points. We consider a generalized Loschmidt echo for the noise-averaged density matrix $\bar\rho$, which is a mixed state in general, as well as the pure state Loschmidt echo calculated for each noise realization with the average performed over the corresponding return rates. $\bar\rho$ can be obtained from a master equation and we show that for two-band models noise destroys its coherences which typically drives $\bar\rho$ towards the completely mixed state which is an attractive fixed point. DQPTs are thus always smoothed out for finite noise. For single noise realizations, on the other hand, we find that DQPTs under certain conditions are always present irrespective of the noise level. This leads to remarkable stable though slightly broadened DQPT-like features in the averaged return rate. We illustrate our results for the XY model by considering a noisy ramp as well as noise in the energy levels of the final Hamiltonian.
- [85] arXiv:2505.22433 (替换) [中文pdf, pdf, 其他]
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标题： 光电子自旋和阳离子取向的对映体敏感锁定标题： Enantiosensitive locking of photoelectron spin and cation orientationPhilip Caesar M. Flores, Stefanos Carlström, Serguei Patchkovskii, Misha Ivanov, Vladimiro Mujica, Andres F. Ordonez, Olga Smirnova主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 光学 (physics.optics) ; 量子物理 (quant-ph)
手性描述了一个物体与其镜像之间的不对称性，这在从分子和聚集体到薄膜和块体手性材料的所有物质尺度上都支撑着多种功能。 一个特别引人入胜的例子是手性诱导的自旋选择性（CISS），其中手性结构以对映体敏感的方式定向电子自旋。 尽管进行了广泛的研究，自旋-手性耦合的基本起源、CISS效应出乎意料的大大小以及电磁场的可能作用仍然不清楚。 在这里，我们通过检查最简单的场景来解决这些问题：随机取向的手性分子的自旋分辨光致电离。 我们发现两种自旋选择性光动力学的普遍几何机制，这些机制仅来自电偶极子相互作用，并且之前未被认识到。 这些机制在各向同性照射下的无定形手性介质中仍有效运作，并在弱自旋-轨道耦合下持续存在，突显了自旋-手性相互作用的基本方面。 我们进一步识别了一个与CISS密切相关但未报告的现象：光电子自旋取向与分子几何结构的锁定。 我们的发现提供了一个统一的几何框架，具有广泛的意义，从CISS和不对称催化到手性晶体中的自旋纹理以及如外尔半金属等手性量子材料。
Chirality describes the asymmetry between an object and its mirror image, underpinning diverse functionalities across all scales of matter-from molecules and aggregates to thin films and bulk chiral materials. A particularly intriguing example is chirality-induced spin selectivity (CISS), where chiral structures orient electron spins enantio-sensitively. Despite extensive research, the fundamental origin of spin-chirality coupling, the unexpectedly large magnitude of the CISS effect, and the possible role of electromagnetic fields remain unclear. Here, we address these issues by examining the simplest scenario: spin-resolved photoionization of randomly oriented chiral molecules. We uncover two universal geometric mechanisms of spin-selective photodynamics, arising solely from electric-dipole interactions and previously unrecognized. These mechanisms operate effectively even in amorphous chiral media under isotropic illumination and persist at weak spin-orbit coupling, underscoring fundamental aspects of spin-chirality interplay. We further identify an unreported phenomenon central to CISS: locking of photoelectron spin orientation to molecular geometry. Our findings provide a unified geometric framework with broad implications, extending from CISS and asymmetric catalysis to spin textures in chiral crystals and chiral quantum materials such as Weyl semimetals.
- [86] arXiv:2507.03115 (替换) [中文pdf, pdf, html, 其他]
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标题： 准守恒定律和弱相互作用局域模型中的抑制输运标题： Quasiconservation Laws and Suppressed Transport in Weakly Interacting Localized Models评论： 35页，23图主题： 强关联电子 (cond-mat.str-el) ; 无序系统与神经网络 (cond-mat.dis-nn) ; 统计力学 (cond-mat.stat-mech) ; 量子物理 (quant-ph)
在存在相互作用的情况下，局域化的稳定性仍然是一个开放问题，有限尺寸效应给数值研究带来了重大挑战。 在本工作中，我们研究了弱相互作用下非相互作用局域化的微扰稳定性，这使我们能够分析更大尺寸的系统。 专注于一维无序安德森模型和准周期阿布里-安德烈模型，使用微扰理论的一阶绝热规范势（AGP），我们计算了非相互作用局域运动积分（LIOMs）的一阶修正。 我们发现，至少$O(1)$分数的LIOMs的修正得到了良好控制并在大系统尺寸下收敛，而其他LIOMs则受到共振的影响。 此外，我们引入并研究了这种弱相互作用模型的电荷输运能力。 在一阶近似下，我们发现电荷输运能力在相互作用存在时仍然受限。 综合这些结果表明，在一阶微扰下，局域化对弱相互作用是微扰稳定的，这意味着至少在反相互作用强度的参数范围内，局域化持续存在。 我们预期这种微扰稳定性在足够强的无序下可以扩展到所有阶次，此时局域化长度较短，代表真正的局域相。 相反，我们的发现表明，之前提出的由相互作用引起的雪崩不稳定性，即在安德森和阿布里-安德烈模型的弱局域化区域中，是一种更微妙的现象，仅在微扰理论的高阶次或通过非微扰效应中出现。
The stability of localization in the presence of interactions remains an open problem, with finite-size effects posing significant challenges to numerical studies. In this work, we investigate the perturbative stability of noninteracting localization under weak interactions, which allows us to analyze much larger system sizes. Focusing on disordered Anderson and quasiperiodic Aubry-Andr\'e models in one dimension, and using the adiabatic gauge potential (AGP) at first order in perturbation theory, we compute first-order corrections to noninteracting local integrals of motion (LIOMs). We find that for at least an $O(1)$ fraction of the LIOMs, the corrections are well-controlled and converge at large system sizes, while others suffer from resonances. Additionally, we introduce and study the charge-transport capacity of this weakly interacting model. To first order, we find that the charge transport capacity remains bounded in the presence of interactions. Taken together, these results demonstrate that localization is perturbatively stable to weak interactions at first order, implying that, at the very least, localization persists for parametrically long times in the inverse interaction strength. We expect this perturbative stability to extend to all orders at sufficiently strong disorder, where the localization length is short, representing the true localized phase. Conversely, our findings suggest that the previously proposed interaction-induced avalanche instability, namely in the weakly localized regime of the Anderson and Aubry-Andr\'e models, is a more subtle phenomenon arising only at higher orders in perturbation theory or through nonperturbative effects.
- [87] arXiv:2507.10690 (替换) [中文pdf, pdf, html, 其他]
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标题： 多体算符的自然超轨道表示标题： Natural super-orbitals representation of many-body operators评论： 16页，9图主题： 强关联电子 (cond-mat.str-el) ; 量子物理 (quant-ph)
我们引入了多体算符的自然超轨道的概念，定义为与矢量化算符相关的单体超密度矩阵的特征向量。 我们将这些对象与与自然超轨道占据相关的算符的非高斯性度量相关联，并定义这种基旋转如何影响算符的非稳定化程度。 我们首先在各种背景下分析这些对象的一般解析性质，包括非相互作用哈密顿量的时间演化算符和哈随机单位变换。 然后，我们对时间演化算符和时间演化局部算符对应的自然超轨道进行了数值研究，重点关注两个多体系统：费米子$t\text{-}V$链和一个杂质模型，使用张量网络模拟。 我们的结果表明，$t\text{-}V$模型缺乏首选的超轨道基，而在杂质模型中，两个算符的自然轨道占据在所有时间都呈指数衰减。 这表明只有少数轨道对量子关联有显著贡献，从而使得在自然轨道基下可以进行紧凑的矩阵乘积算符表示，并减少非稳定化程度。 最后，我们研究了杂质模型中时间演化局部算符的自然轨道的空间扩展，并表明该算符在自然轨道基下的复杂度随时间趋于饱和。 这一新框架为未来的研究打开了大门，利用其自然超轨道基下算符的压缩结构，例如在大相互作用系统中长时间尺度上的非时序关联函数的计算。
We introduce the concept of natural super-orbitals for many-body operators, defined as the eigenvectors of the one-body super-density matrix associated with a vectorized operator. We relate these objects to measures of non-Gaussianity of operators associated to the occupations of the natural super-orbitals, and define how the non-stabilizerness of operators can be affected by such a basis rotation. We first analyze the general analytical properties of these objects in various contexts, including the time-evolution operator of non-interacting Hamiltonians and Haar-random unitaries. We then perform a numerical investigation of the natural super-orbitals corresponding to both the time-evolution operator and a time-evolved local operator, focusing on two many-body systems: the fermionic $t\text{-}V$ chain and an impurity model, using tensor network simulations. Our results reveal that the $t\text{-}V$ model lacks a preferred super-orbital basis, while in the impurity model, the occupations of the natural orbitals for both operators decay exponentially at all times. This indicates that only a small number of orbitals contribute significantly to quantum correlations, enabling a compact matrix-product-operator representation and a reduced non-stabilizerness in the natural orbital basis. Finally, we examine the spatial spread of the natural orbitals for time-evolved local operators in the impurity model and show that the complexity of this operator in the natural orbital basis saturates over time. This new framework opens the door to future research that leverages the compressed structure of operators in their natural super-orbital basis, enabling for instance the computation of out-of-time-order correlators in large interacting systems over extended time scales.
- [88] arXiv:2507.23729 (替换) [中文pdf, pdf, html, 其他]
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标题： 黑洞散射导致的纠缠抑制标题： Entanglement Suppression Due to Black Hole Scattering评论： 51页，19图；错误更正主题： 高能物理 - 理论 (hep-th) ; 强关联电子 (cond-mat.str-el) ; 量子物理 (quant-ph)
我们考虑二维共形场理论中纠缠熵的演化，该理论具有全息对偶。 具体而言，我们感兴趣的是由纯态（局部算符）和混合态局部淬火组合产生的激发态类别。 我们采用一种方法，使我们能够解析地确定完整的时间演化。 虽然单个局部算符的插入相对于真空会产生纠缠熵的对数时间轮廓，但我们发现，在存在混合态淬火的情况下，这种增长被大大抑制，使其变为时间不变的常数波动。 抑制的程度取决于淬火的相对位置以及与淬火相关的正则化参数的比值。 这项工作揭示了涉及黑洞的引力散射有趣特性。
We consider the evolution of entanglement entropy in a two-dimensional conformal field theory with a holographic dual. Specifically, we are interested in a class of excited states produced by a combination of pure-state (local operator) and mixed-state local quenches. We employ a method that allows us to determine the full time evolution analytically. While a single insertion of a local operator gives rise to a logarithmic time profile of entanglement entropy relative to the vacuum, we find that this growth is heavily suppressed in the presence of a mixed-state quench, reducing it to a time-independent constant bump. The degree of suppression depends on the relative position of the quenches as well as the ratio of regularization parameters associated with the quenches. This work sheds light on the interesting properties of gravitational scattering involving black holes.
- [89] arXiv:2508.00840 (替换) [中文pdf, pdf, html, 其他]
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标题： 基于自适应瑞尼熵优化的抗量子RSA模分解标题： Quantum-Resistant RSA Modulus Decomposition via Adaptive Rényi Entropy Optimization评论： 11页，2表主题： 密码学与安全 (cs.CR) ; 数论 (math.NT) ; 量子物理 (quant-ph)
本文探讨了一种理论方法，通过利用Rényi熵约束优化素数选择，以增强RSA对量子攻击的抵抗能力。 我们构建了一个框架，其中素数以受控的接近性（$|p-q| < \gamma\sqrt{pq}$）生成，以最小化量子周期查找算子的碰撞熵 $\mathscr{H}_2$。 主要贡献包括：(1) 通过Maynard的素数间隔定理建立素数分布特性与量子攻击复杂度之间的联系，(2) 提供在熵约束下素数存在的构造性证明，以及(3) 在量子随机预言模型下将安全性归约到理想格问题。 理论分析表明，对于具有$\gamma < k^{-1/2+\epsilon}$的$k$位模数，Shor算法需要$\Omega(\gamma^{-1}k^{3/2})$个量子操作，同时保持与标准 RSA 相当的经典安全性。 关键改进：(1) 通过Maynard定理证明素数存在性（定理3.1），(2) 用于SVP归约的理想格嵌入（定理5.3），(3) 用于信息论分析的量子Fano界（定理6.3），(4) 多素数RSA扩展（第7.3节）。
This paper explores a theoretical approach to enhance RSA's resistance against quantum attacks by optimizing prime selection through R\'enyi entropy constraints. We develop a framework where primes are generated with controlled proximity ($|p-q| < \gamma\sqrt{pq}$) to minimize the collision entropy $\mathscr{H}_2$ of the quantum period-finding operator. The main contributions include: (1) establishing a connection between prime distribution properties and quantum attack complexity via Maynard's prime gap theorem, (2) providing a constructive proof for prime existence under entropy constraints, and (3) demonstrating security reduction to ideal lattice problems under the quantum random oracle model. Theoretical analysis suggests that for $k$-bit moduli with $\gamma < k^{-1/2+\epsilon}$, Shor's algorithm requires $\Omega(\gamma^{-1}k^{3/2})$ quantum operations while maintaining classical security equivalent to standard RSA. Key Enhancements: (1) Prime existence proof via Maynard's theorem (Theorem 3.1), (2) Ideal lattice embedding for SVP reduction (Theorem 5.3), (3) Quantum Fano bound for information-theoretic analysis (Theorem 6.3), (4) Multi-prime RSA extension (Section 7.3).