论文标题
用于估计量子状态非线性功能的混合框架
A hybrid framework for estimating nonlinear functions of quantum states
论文作者
论文摘要
估计量子状态的非线性功能，例如$ \ tr（ρ^m）$的那一刻，对量子科学和技术具有基本和实际兴趣。在这里，我们显示了一个量子古典混合框架来测量它们，其中量子部分由广义交换测试构成，并且经典部分是通过在随机测量中通过后处理来实现的。该混合框架利用了中间量子处理器的部分相干功率，同时大大减少了量子测量的数量和经典后处理的成本。我们证明了我们的框架在国家时刻估计和缓解量子误差的任务中的优势。
Estimating nonlinear functions of quantum states, such as the moment $\tr(ρ^m)$, is of fundamental and practical interest in quantum science and technology. Here we show a quantum-classical hybrid framework to measure them, where the quantum part is constituted by the generalized swap test, and the classical part is realized by postprocessing the result from randomized measurements. This hybrid framework utilizes the partial coherent power of the intermediate-scale quantum processor and, at the same time, dramatically reduces the number of quantum measurements and the cost of classical postprocessing. We demonstrate the advantage of our framework in the tasks of state-moment estimation and quantum error mitigation.
