On confined fractional charges: a simple model

TL;DR

This paper presents a simple lattice model demonstrating confined fractional charges analogous to QCD, showing how vacuum effects lead to a linear confining force between fractionalized excitations.

Contribution

It introduces a minimal solid-state model where fractional charges are confined, revealing vacuum polarization effects similar to those in quantum chromodynamics.

Findings

Fractional charges of ±e/2 are supported at string ends.

A constant confining force acts between fractional charges.

Vacuum polarization reduces fluctuations near strings.

Abstract

We address the question whether features known from quantum chromodynamics (QCD) can possibly also show up in solid-state physics. It is shown that spinless fermions of charge $e$ on a checkerboard lattice with nearest-neighbor repulsion provide for a simple model of confined fractional charges. After defining a proper vacuum the system supports excitations with charges $\pm e/2$ attached to the ends of strings. There is a constant confining force acting between the fractional charges. It results from a reduction of vacuum fluctuations and a polarization of the vacuum in the vicinity of the connecting strings.