Suppression of Persistent Currents in 1-D Disordered Rings by Coulomb Interaction

TL;DR

This study numerically investigates how Coulomb interactions suppress persistent currents in disordered one-dimensional rings, revealing that stronger interactions lead to greater suppression, especially in larger rings, with no observed enhancement.

Contribution

It demonstrates the suppression effect of Coulomb interactions on persistent currents in disordered 1D rings using numerical methods and validates the Hartree-Fock approximation for small systems.

Findings

Persistent current amplitude decreases with increasing Coulomb interaction.

Suppression effect is more pronounced in larger rings.

No enhancement of current by electron-electron interaction observed.

Abstract

Effects of Coulomb interaction on persistent currents in disordered one-dimensional rings are numerically investigated. First of all effectiveness of the Hartree-Fock approximation is established on small systems. Then the calculations are done for systems with 40 electrons in 100 sites. It is found that the amplitude of the average persistent current in the diffusive regime is suppressed as the strength of the Coulomb interaction increases. The suppression of the current is stronger in larger rings than in smaller ones. The enhancement of the current by the electron-electron interaction was not observed in the diffusive regime.