Effect of Increasing Disorder on the Critical Behavior of a Coulomb System

TL;DR

This study uses Monte Carlo simulations to examine how increasing positional disorder affects the phase transition and critical behavior of a three-dimensional Coulomb system, revealing that disorder lowers transition temperature and alters critical exponents.

Contribution

It systematically investigates the impact of disorder on Coulomb systems' critical behavior using finite size scaling and Monte Carlo methods, extending understanding of Coulomb glasses.

Findings

Transition temperature T_C decreases with disorder

Critical exponent nu increases with disorder

Specific heat and density of states change with disorder

Abstract

We have performed a Monte Carlo study of a classical three dimensional Coulomb system in which we systematically increase the positional disorder. We start from a completely ordered system and gradually transition to a Coulomb glass. The phase transition as a function of temperature is second order for all values of disorder. We use finite size scaling to determine the transition temperature T_C and the critical exponent nu. We find that T_C decreases and that nu increases with increasing disorder. We also observe changes in the specific heat, the single particle density of states, and the staggered occupation as a function of disorder and temperature.