Fractional electric charge of a magnetic vortex at nonzero temperature

TL;DR

This paper investigates how a two-dimensional Dirac fermion gas in a magnetic vortex background acquires fractional electric charge at finite temperatures, analyzing the dependence on temperature, flux, and boundary conditions.

Contribution

It provides a detailed analysis of the temperature-dependent fractional charge and charge fluctuations in a Dirac fermion system with a magnetic vortex, including boundary condition effects.

Findings

Fractional charge appears at nonzero temperature.

Charge and fluctuation depend on vortex flux and boundary conditions.

Explicit functional forms of charge and fluctuations are derived.

Abstract

An ideal gas of twodimensional Dirac fermions in the background of a pointlike magnetic vortex with arbitrary flux is considered. We find that this system acquires fractional electric charge at finite temperatures and determine the functional dependence of the thermal average and quadratic fluctuation of the charge on the temperature, the vortex flux, and the continuous parameter of the boundary condition at the location of the vortex.