标题： 观察偶极 Rydberg 量子自旋链中的弱破坏守恒定律 显示英文标题

标题： Observing weakly broken conservation laws in a dipolar Rydberg quantum spin chain

摘要： 可积的量子多体系统包含广泛的守恒定律家族，其中一些是脆弱的：即使是非常微小的扰动也可以定性地改变它们的动力学约束。 在这里，我们表明这种脆弱性在一个由最少14个里德伯原子组成的一维量子自旋链中留下了清晰的实验特征。 来自原子间偶极耦合的弱可积性破坏在非局部可观测量的动力学中可以在实验可访问的时间内直接检测到。 特别是，磁化率波动对脆弱守恒定律的破坏非常敏感，并表现出异常增长，我们在实验中观察到了这一点；类似的特征也出现在一个半局部字符串可观测量中。 在更长的链上进行的数值模拟以及一个简化的经典随机模型重现了这些特征。 我们确立了非局部可观测量作为量子自旋链中脆弱守恒定律的敏感探测器，并将里德伯原子阵列作为测试弱可积性破坏的量子多体动力学微扰描述的平台。 显示英文摘要

摘要： Integrable quantum many-body systems host families of extensive conservation laws, some of which are fragile: even infinitesimal perturbations can qualitatively alter their dynamical constraints. Here we show that this fragility leaves a clear experimental fingerprint in a one-dimensional quantum spin chain of as few as 14 Rydberg atoms. Weak integrability breaking from interatomic dipolar couplings is directly detectable within experimentally accessible times in the dynamics of non-local observables. In particular, magnetization fluctuations are highly sensitive to the breaking of fragile conservation laws and exhibit anomalous growth, which we observe experimentally; similar signatures appear in a semilocal string observable. Numerical simulations on substantially longer chains and a simplified classical stochastic model reproduce those features. We establish non-local observables as a sensitive probe of fragile conservation laws in quantum spin chains and Rydberg-atom arrays as a platform to test perturbative descriptions of quantum many-body dynamics with weak integrability breaking.