Study of the one dimensional Holstein model using the augmented space approach

TL;DR

This paper introduces a new augmented space recursion formalism to analyze ground state properties of one-dimensional Holstein models, effectively handling both ordered and disordered cases across various regimes.

Contribution

The paper presents a novel formalism that unifies the treatment of ordered and disordered Holstein models, matching existing results and extending analysis to disordered systems.

Findings

Method matches exact diagonalization and DMRG results for ordered systems.

Effectively handles phononic and substitutional disorder.

Applicable across all parametric regimes for ordered systems.

Abstract

A new formalism using the ideas of the augmented space recursion (introduced by one of us) has been proposed to study the ground state properties of ordered and disordered one-dimensional Holstein model. For ordered case our method works equally well in all parametric regime and matches with the existing exact diagonalization and DMRG results. On the other hand the quenched substitutionally disordered model works in low and intermediate regime of electron phonon coupling. Effect of phononic and substitutional disorder are treated on equal footing.