Ying Wenxiang, Su Yu, Chen Zi-Hao, Wang Yao, Huo Pengfei
Department of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, USA.
Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
J Chem Phys. 2024 Oct 14;161(14). doi: 10.1063/5.0225734.
We investigate the quantum dynamics of a spin coupling to a bath of independent spins via the dissipaton equation of motion (DEOM) approach. The bath, characterized by a continuous spectral density function, is composed of spins that are independent level systems described by the su(2) Lie algebra, representing an environment with a large magnitude of anharmonicity. Based on the previous work by Suarez and Silbey [J. Chem. Phys. 95, 9115 (1991)] and by Makri [J. Chem. Phys. 111, 6164 (1999)] that the spin bath can be mapped to a Gaussian environment under its linear response limit, we use the time-domain Prony fitting decomposition scheme to the bare-bath time correlation function (TCF) given by the bosonic fluctuation-dissipation theorem to generate the exponential decay basis (or pseudo modes) for DEOM construction. The accuracy and efficiency of this strategy have been explored by a variety of numerical results. We envision that this work provides new insights into extending the hierarchical equations of motion and DEOM approach to certain types of anharmonic environments with arbitrary TCF or spectral density.
我们通过运动耗散方程（DEOM）方法研究了一个自旋与独立自旋库耦合的量子动力学。该自旋库由具有连续谱密度函数表征，它由服从su(2)李代数描述的独立能级系统的自旋组成，代表了一个具有大非谐性的环境。基于苏亚雷斯和西尔贝[《化学物理杂志》95, 9115 (1991)]以及马克里[《化学物理杂志》111, 6164 (1999)]之前的工作，即在其线性响应极限下自旋库可映射到高斯环境，我们对由玻色子涨落 - 耗散定理给出的裸库时间关联函数（TCF）采用时域普罗尼拟合分解方案，以生成用于构建DEOM的指数衰减基（或伪模）。通过各种数值结果探索了该策略的准确性和效率。我们设想这项工作为将运动层次方程和DEOM方法扩展到具有任意TCF或谱密度的某些类型的非谐环境提供了新的见解。
