Generalization of the hierarchical equations of motion theory for efficient calculations with arbitrary correlation functions
Abstract
The hierarchical equations of motion (HEOM) theory is one of the standard methods to rigorously describe open quantum dynamics coupled to harmonic environments. Such a model is used to capture nonMarkovian and nonperturbative effects of environments appearing in ultrafast phenomena. In the regular framework of the HEOM theory, the environment correlation functions are restricted to linear combinations of exponential functions. In this article, we present a new formulation of the HEOM theory including treatment of nonexponential correlation functions, which enables us to describe general environmental effects more efficiently and stably than the original theory and other generalizations. The library and its Python binding we developed to perform simulations based on our approach, named LibHEOM and PyHEOM, respectively, are provided as the supplementary material.
 Publication:

Journal of Chemical Physics
 Pub Date:
 May 2020
 DOI:
 10.1063/5.0007327
 arXiv:
 arXiv:2003.06134
 Bibcode:
 2020JChPh.152t4101I
 Keywords:

 Physics  Chemical Physics;
 Condensed Matter  Statistical Mechanics;
 Quantum Physics
 EPrint:
 18 pages, 6 figures