Relevant coherent states method for the quantum adiabatic dynamics of lattice-coupled charge carriers

TL;DR

The paper introduces a novel numerical method using coherent states to analyze low-frequency quantum lattice dynamics, successfully capturing the adiabatic crossover in polaron behavior in the Holstein model.

Contribution

A new coherent states-based numerical approach is developed to study adiabatic quantum lattice dynamics, including the challenging adiabatic limit.

Findings

Accurate calculation of polaron band structure in the Holstein model.

Successful description of the crossover between small and large adiabatic polarons.

Effective treatment of spatial correlations in polaron dispersion.

Abstract

A new numerical method is proposed for determining the low-frequency dynamics of the charge carrier coupled to the deformable quantum lattice. As an example, the polaron band structure is calculated for the one-dimensional Holstein model. The adiabatic limit on the lattice, which cannot be reached by other approaches, is investigated. In particular, an accurate description is obtained of the crossover between quantum small adiabatic polarons, pinned by the lattice, and large adiabatic polarons, moving along the continuum as classical particles. It is shown how the adiabatic contributions to the polaron dispersion, involving spatial correlations over multiple lattice sites, can be treated easily in terms of coherent states.