Glassy Relaxation and Breakdown of the Stokes-Einstein Relation in the Two Dimensional Lattice Coulomb Gas of Fractional Charges

TL;DR

This study uses Monte Carlo simulations to analyze the relaxation dynamics of a 2D lattice Coulomb gas with fractional charges, revealing a violation of the Stokes-Einstein relation at low temperatures linked to microscopic heterogeneity.

Contribution

It demonstrates the breakdown of the Stokes-Einstein relation in a 2D Coulomb gas with fractional charges, providing insights into glassy relaxation phenomena.

Findings

Stokes-Einstein relation is violated at low temperatures

Fractional power law relation between diffusion coefficient and relaxation time

Microscopic heterogeneity underlies the violation

Abstract

We present Monte Carlo simulation results on the equilibrium relaxation of the two dimensional lattice Coulomb gas with fractional charges, which exhibits a close analogy to the primary relaxation of fragile supercooled liquids. Single particle and collective relaxation dynamics show that the Stokes-Einstein relation is violated at low temperatures, which can be characterized by a fractional power law relation between the self-diffusion coefficient and the characteristic relaxation time. The microscopic spatially heterogeneous structure responsible for the violation is identified.