Persistent currents in two dimensions: New regimes induced by the interplay between electronic correlations and disorder

TL;DR

This paper investigates how electronic correlations and disorder influence persistent currents in two-dimensional lattice systems, revealing distinct regimes where the current behavior varies with interaction strength and disorder.

Contribution

It introduces a method to distinguish continuum-like and lattice regimes in disordered, interacting electron systems using persistent current measurements.

Findings

Persistent current I is proportional to total momentum K in the continuum limit.

I remains independent of interaction strength U when K is conserved in the continuum regime.

In lattice regimes, I decays as U increases with disorder W varied.

Abstract

Using the persistent current I induced by an Aharonov-Bohm flux in square lattices with random potentials, we study the interplay between electronic correlations and disorder upon the ground state (GS) of a few polarized electrons (spinless fermions) with Coulomb repulsion. K being the total momentum, we show that I is proportional to K in the continuum limit. We use this relation to distinguish between the continuum regimes, where the lattice GS behaves as in the continuum limit and I is independent of the interaction strength U when K is conserved, and the lattice regimes where I decays as U increases. Changing the disorder strength W and U, we obtain many regimes which we study using the map of local currents carried by three spinless fermions.