Han J, Cai W, Hu L, Mu X, Ma Y, Xu Y, Wang W, Wang H, Song Y P, Zou C-L, Sun L
Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China.
CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026, China.
Phys Rev Lett. 2021 Jul 9;127(2):020504. doi: 10.1103/PhysRevLett.127.020504.
Digital quantum simulators provide a diversified tool for solving the evolution of quantum systems with complicated Hamiltonians and hold great potential for a wide range of applications. Although much attention is paid to the unitary evolution of closed quantum systems, dissipation and noise are vital in understanding the dynamics of practical quantum systems. In this work, we experimentally demonstrate a digital simulation of an open quantum system in a controllable Markovian environment with the assistance of a single ancillary qubit. By Trotterizing the quantum Liouvillians, the continuous evolution of an open quantum system is effectively realized, and its application in error mitigation is demonstrated by adjusting the simulated noise intensities. High-order Trotter for open quantum dynamics is also experimentally investigated and shows higher accuracy. Our results represent a significant step toward hardware-efficient simulation of open quantum systems and error mitigation in quantum algorithms in noisy intermediate-scale quantum systems.
数字量子模拟器为求解具有复杂哈密顿量的量子系统的演化提供了一种多样化工具，在广泛的应用中具有巨大潜力。尽管人们对封闭量子系统的幺正演化给予了很多关注，但耗散和噪声对于理解实际量子系统的动力学至关重要。在这项工作中，我们借助单个辅助量子比特，在可控的马尔可夫环境中通过实验演示了一个开放量子系统的数字模拟。通过对量子刘维尔算符进行 Trotter 分解，有效实现了开放量子系统的连续演化，并通过调整模拟噪声强度展示了其在误差缓解方面的应用。还通过实验研究了用于开放量子动力学的高阶 Trotter 方法，结果显示其具有更高的精度。我们的结果代表了朝着在有噪声的中等规模量子系统中高效模拟开放量子系统以及在量子算法中进行误差缓解迈出的重要一步。
