From the Fermi glass towards the Mott insulator in one dimension: Delocalization and strongly enhanced persistent currents

TL;DR

This paper investigates how the interplay of disorder and interactions in a one-dimensional fermionic system can significantly enhance persistent currents, bridging the Fermi glass and Mott insulator phases.

Contribution

It demonstrates the dramatic increase in persistent currents due to the competition between Anderson localization and Mott insulating behavior using DMRG simulations.

Findings

Persistent currents can be enhanced by orders of magnitude.

Transition from Anderson insulator to Mott insulator affects current magnitude.

Ground state energy changes under twisted boundary conditions reveal phase competition.

Abstract

When a system of spinless fermions in a disordered mesoscopic ring becomes instable between the inhomogeneous configuration driven by the random potential (Anderson insulator) and the homogeneous one driven by repulsive interactions (Mott insulator), the persistent current can be enhanced by orders of magnitude. This is illustrated by a study of the change of the ground state energy under twisted boundary conditions using the density matrix renormalization group algorithm.