标题： 虚时谱变换用于激发态制备 显示英文标题

标题： Imaginary Time Spectral Transforms for Excited State Preparation

摘要： 多体量子系统的激发态在广泛的物理和化学现象中起着关键作用。 与存在许多高效变分技术的基态不同，目前在经典或量子硬件上系统构建通用量子系统激发态的方法很少。 为了解决这一挑战，我们引入了一种通用方法，使我们能够在给定能量下获得量子系统的任意本征态。 通过将移位-倒置机制与虚时间演化相结合，我们能够避免哈密顿量的显式逆运算，并构建大尺度多体量子系统的激发本征态。 我们通过将其应用于大型无序自旋链，在经典计算机上展示了该技术。 基于此方法，我们提出了一种适用于未来不久的量子硬件的混合方案。 显示英文摘要

摘要： Excited states of many-body quantum systems play a key role in a wide range of physical and chemical phenomena. Unlike ground states, for which many efficient variational techniques exist, there are few ways to systematically construct excited states of generic quantum systems on either classical or quantum hardware. To address this challenge, we introduce a general approach that allows us to obtain arbitrary eigenstates of quantum systems at a given energy. By combining the shift-invert mechanism with imaginary time evolution, we are able to avoid explicit inversion of the Hamiltonian and construct excited eigenstates of large many-body quantum systems. We demonstrate the technique classically by applying it to large disordered spin chains. Based on this approach, we propose a hybrid scheme suitable for near-future quantum hardware.