Link auxiliary field method in the Extended Hubbard model

TL;DR

This paper extends the Hubbard field method in fermion Quantum Monte Carlo simulations to include link fields, improving stability, reliability, and efficiency in energy calculations.

Contribution

It introduces Hubbard link fields to better model interactions, enhancing simulation stability and reducing autocorrelation issues in fermion Quantum Monte Carlo methods.

Findings

More stable energy computations with five fields

Reduced autocorrelations and metastable states

Improved thermalization in simulations

Abstract

The aim of this work is to generalize the method of Hubbard fields in fermion Quantum Monte Carlo simulation to the case of link fields. The introduced Hubbard link fields play a role of the interaction fields responsible for the attraction and repulsion of electronic excitations at the nodes. Such improvements leads to a number of advantages concerning thermalization time, autocorrelations, metastable states and probability distributions of the quantities. It is demonstrated that computations using five fields are more stable and reliable in case of energy observables.