热噪声环境下的量子调控优化  

Quantum control optimization in thermal noise environment

作　　者：刘学铭 陈永聪 敖平 LIU Xueming;CHEN Yongcong;AO Ping(College of Sciences,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学理学院,上海200444

出　　处：《量子电子学报》2024年第1期103-112,共10页Chinese Journal of Quantum Electronics

基　　金：国家自然科学基金(563 16Z103060007)。

摘　　要：环境热噪声是量子计算走向规模化的一大阻碍,其存在对量子调控过程的鲁棒性和保真度提出了更高要求。采用随机动力学结构分解方法,并根据Kubo-Einstein涨落耗散定理,研究了热噪声环境下量子调控的量子动力学优化问题,即如何提高热噪声环境下量子调控过程的保真度。基于二维球面上的经典路径可完全描述单个量子比特运动这一特性,提出了基于梯度下降算法的变分优化方案,并通过数值模拟证明了该方案的可用性。结果发现,在经典极限下影响量子调控过程保真度的主要因素是热涨落。该方法有望与实验相互验证,进一步指导和评估实验方案,以期实现量子门的高保真度。Thermal noise presents a major obstacle for quantum computing to scale up,and its existence puts stricter requirements on the robustness and fidelity of quantum control process.This work adopts the stochastic dynamic structure decomposition method and applies the Kubo-Einstein fluctuation dissipation theorem to the optimization of quantum dynamics,that is,how to improve the fidelity of quantum control process under thermal noise environment.Based on the characteristic that the classical path on a two-dimensional sphere can completely describe the motion of a single qubit,the research proposes a variational optimization scheme of gradient descent algorithm to reduce the thermal effect,and demonstrates its applicability via numerical simulation.It is found that the main factor affecting the fidelity of quantum control process under classical limit is thermal fluctuation.The method is expected to be mutually validated with experiments,and thus can further guide and evaluate experimental schemes towards achieving high fidelity of quantum gates.

关 键 词：量子信息 量子调控 量子比特 噪声环境 优化过程 

分 类 号：O413.1[理学—理论物理]