Spectral Functions for the Holstein Model

TL;DR

This paper introduces a method to compute electronic spectral functions in the Holstein model by transforming and diagonalizing an effective Hamiltonian that includes the symmetric phonon mode often neglected.

Contribution

It presents a novel approach to incorporate the symmetric phonon mode into spectral function calculations using exact numerical diagonalization.

Findings

Successfully computes spectral functions including symmetric phonon mode

Demonstrates the importance of the symmetric phonon mode in spectral analysis

Provides a new computational framework for the Holstein model

Abstract

We perform an unitary transformation for the symmetric phonon mode of the Holstein molecular crystal hamiltonian. We show how to compute the electronic spectral functions by exact numerical diagonalisation of an effective hamiltonian fully taking account of the symmetric phonon mode, usually discarded.