论文标题
量化模拟量子模拟中错误的敏感性
Quantifying the sensitivity to errors in analog quantum simulation
论文作者
论文摘要
量子模拟器被广泛视为量子技术最有希望的近期应用之一。但是，在存在不可避免的缺陷的情况下，嘈杂的设备在多大程度上尚不清楚在多大程度上可以输出可靠的结果。在这里，我们提出了一个框架来表征量子模拟器的性能，通过将测得的量子期望值的鲁棒性与可观察到的输出的频谱特性联系起来，这又可以与其宏观或显微镜特征相关联。我们表明，在一般的假设和平均所有状态下，不完美的设备能够准确地重现宏观可观察物的动力学，而显微镜可观察物的期望值相对误差平均要大得多。我们在实验中证明了这些特征在最先进的量子模拟器中的普遍性，并表明预测的行为对于高度精确的设备是一般性的，而无需假设有关完美之处的性质。
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. 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.
