A variational surface hopping algorithm for the sub-Ohmic spin-boson model

TL;DR

This paper introduces a surface hopping algorithm based on the Davydov D1 ansatz for simulating spin dynamics in the sub-Ohmic spin-boson model, accurately capturing both coherent and incoherent behaviors.

Contribution

It develops a novel surface hopping algorithm utilizing the Davydov D1 ansatz, improving the simulation of spin-boson dynamics by closely following Marcus theory.

Findings

Hopping rates align more closely with Marcus formula

Algorithm effectively captures both coherent and incoherent dynamics

Provides a unified approach for population evolution

Abstract

The Davydov D1 ansatz, which assigns an individual bosonic trajectory to each spin state, is an efficient, yet extremely accurate trial state for time-dependent variation of the sub-Ohmic spin-boson model [J. Chem. Phys. 138, 084111 (2013)]. A surface hopping algorithm is developed employing the Davydov D1 ansatz to study the spin dynamics with a sub-Ohmic bosonic bath. The algorithm takes into account both coherent and incoherent dynamics of the population evolution in a unified manner, and compared with semiclassical surface hopping algorithms, hopping rates calculated in this work follow more closely the Marcus formula.