论文标题
通过定期驾驶探测量子演变的单位性
Probing The Unitarity of Quantum Evolution Through Periodic Driving
论文作者
论文摘要
随着量子计算机和模拟器开始产生无法经典验证的结果，必须开发各种工具来检测和诊断这些设备上的实验错误。尽管状态或过程断层扫描是表征实验错误来源的一种自然方法，但强烈的测量要求使这些策略在最小的量子系统以外的所有方面都是不可行的。在这项工作中，我们根据定期驱动的量子系统的特定特性制定单位进化的特征。这些签名的不存在表明在演变上的单位性或周期性条件中存在断裂。我们使用这些签名在被困的离子量子计算机上实验检测到不一致的错误。我们的方法基于对单个可观察的重复测量，这使得这是对误差的低成本评估，其测量要求根据动力学的特征而不是系统大小来缩放。
As quantum computers and simulators begin to produce results that cannot be verified classically, it becomes imperative to develop a variety of tools to detect and diagnose experimental errors on these devices. While state or process tomography is a natural way to characterize sources of experimental error, the intense measurement requirements make these strategies infeasible in all but the smallest of quantum systems. In this work, we formulate signatures of unitary evolution based on specific properties of periodically driven quantum systems. The absence of these signatures indicates a break either in the unitarity or periodicity condition on the evolution. We experimentally detect incoherent error on a trapped-ion quantum computer using these signatures. Our method is based on repeated measurements of a single observable, making this a low-cost evaluation of error with measurement requirements that scales according to the character of the dynamics, rather than the system size.
