有限温量子自旋-玻色模型的动力学研究

Dynamics of Finite Temperature Quantum Spin-bose Model

利用Davydov-Ansatze试探波函数研究有限温量子自旋玻色模型的动力学问题,提出一种基于Dirac-Frenkel含时变分并结合正则系综的统计采样技术,可较精确、高效地求解分子聚集体或集光复合物中的激子及电荷转移的动力学问题。在不同谱密度耦合强度、不同电子耦合常数等参数下,演算系统布居数(Population)的动力学演化过程,结果表明:系统在低温的欧姆或亚欧姆环境下,采用试探波函数法得到的结果和采用准绝热传播路径积分法相比,两者具有较好的吻合度。

In this paper,the dynamics of the finite-temperature quantum Spin-bose model is studied by using Davydov-Ansatze wave function method.It is based on the Dirac-Frenkel time-dependent variational principle and the statistical sampling of canonical ensemble.It can be used to solve the exciton and charge transfer dynamics in the molecular aggregates or the light-collecting complexes accurately and efficiently.Under the parameters of different spectral density coupling strength and different electronic coupling constants,the dynamic evolution processes of the population of the system were calculated.The results show that the method of the trial wave function is in good agreement with QUAPI at the low temperature for the Ohmic or the sub-Ohmic environment.