Fast algorithms of bath calculations in simulations of quantum system-bath dynamics
Fast algorithms of bath calculations in simulations of quantum system-bath dynamics
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DOI：
10.1016/j.cpc.2022.108417
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发表时间：
2022-02
期刊：
影响因子：
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通讯作者：
Zhenning Cai;Jianfeng Lu;Siyao Yang
中科院分区：
文献类型：
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作者：
Zhenning Cai;Jianfeng Lu;Siyao Yang
我们提出了Dyson级数求和的快速算法，并给出了耦合谐振腔量子系统的尺蠖蒙特卡罗方法。该算法是基于不断发展的积分微分方程，其中最昂贵的部分来自浴影响泛函的计算。为了加快计算速度，我们设计了快速算法的基础上重用浴影响泛函计算在以前的时间步骤，以减少计算的数量。它被证明，所提出的快速算法减少了这种计算的数量的一个因素O（N），其中N是时间步的总数。数值实验表明了该方法的有效性，并验证了理论结果。
We present fast algorithms for the summation of Dyson series and the inchworm Monte Carlo method for quantum systems that are coupled with harmonic baths. The algorithms are based on evolving the integro-differential equations where the most expensive part comes from the computation of bath influence functionals. To accelerate the computation, we design fast algorithms based on reusing the bath influence functionals computed in the previous time steps to reduce the number of calculations. It is proven that the proposed fast algorithms reduce the number of such calculations by a factor of O (N), where N is the total number of time steps. Numerical experiments are carried out to show the efficiency of the method and to verify the theoretical results.