Quantifying the Sensitivity to Errors in Analog Quantum Simulation
Quantifying the Sensitivity to Errors in Analog Quantum Simulation
复制标题
DOI：
10.1103/prxquantum.1.020308
复制
发表时间：
2020-07
期刊：
影响因子：
--
通讯作者：
P. Poggi;Nathan K. Lysne;Kevin W. Kuper;I. Deutsch;P. Jessen
中科院分区：
文献类型：
--
作者：
P. Poggi;Nathan K. Lysne;Kevin W. Kuper;I. Deutsch;P. Jessen
量子模拟器被广泛认为是量子技术最有前途的近期应用之一。然而，目前尚不清楚，在存在不可避免的缺陷的情况下，噪音设备能在多大程度上输出可靠的结果。在这里，我们提出了一个框架来表征量子模拟器的性能，通过将测量的量子期望值的稳健性与输出可观测值的光谱属性联系起来，而输出可观测值又可以与其在希尔伯特空间中的宏观或微观特征相关联。结果表明，在一般假设下，在所有状态的平均情况下，非理想装置能够准确地再现宏观可观测的动力学，而微观可观测的期望值的平均相对误差要大得多。我们在最先进的量子模拟器中实验演示了这些特征的普遍性，并表明预测的行为对于高精度的设备是通用的，而不假设任何关于缺陷性质的知识。
Quantum simulators are widely seen as one of the most promising near-term applications of quantum technologies. However, it remains unclear to what extent a noisy device can output reliable results in the presence of unavoidable imperfections. Here we propose a framework to characterize the performance of quantum simulators by linking the robustness of measured quantum expectation values to the spectral properties of the output observable, which in turn can be associated with its macroscopic or microscopic character in Hilbert space. We show that, under general assumptions and on average over all states, imperfect devices are able to reproduce the dynamics of macroscopic observables accurately, while the relative error in the expectation value of microscopic observables is much larger on average. We experimentally demonstrate the universality of these features in a state-of-the-art quantum simulator and show that the predicted behavior is generic for a highly accurate device, without assuming any knowledge about the nature of the imperfections.