论文标题
关于量子状态的经典和混合阴影
On Classical and Hybrid Shadows of Quantum States
论文作者
论文摘要
经典阴影是一种在经典计算机上存储量子状态的计算有效方法，目的是估计通过执行重复的随机测量获得的局部可观察物的期望值。在本说明中，我们对此方法提供了一些评论。我们注意到，形成具有有界相对误差的经典阴影所需的资源在很大程度上取决于目标状态。然后，我们评论使用经典阴影来模拟多体动力学的优点和局限性。此外，我们介绍了由系统的一部分而不是整体上的测量结果构成的混合阴影的概念，该框架提供了一个框架，以更深入地了解阴影状态的性质，因为一个人可以减少所测量的子系统的大小，并可以替代压缩量子状态的潜在替代方案。
Classical shadows are a computationally efficient approach to storing quantum states on a classical computer for the purposes of estimating expectation values of local observables, obtained by performing repeated random measurements. In this note we offer some comments on this approach. We note that the resources needed to form classical shadows with bounded relative error depend strongly on the target state. We then comment on the advantages and limitations of using classical shadows to simulate many-body dynamics. In addition, we introduce the notion of a hybrid shadow, constructed from measurements on a part of the system instead of the entirety, which provides a framework to gain more insight into the nature of shadow states as one reduces the size of the subsystem measured, and a potential alternative to compressing quantum states.
