Persistent currents with long-range hopping in 1D single-isolated-diffusive rings

TL;DR

This paper demonstrates through exact calculations that long-range hopping in a disordered 1D ring model explains the observed persistent currents' amplitude and flux-periodicity, showing significant enhancement over previous models.

Contribution

It introduces a simple tight-binding model with long-range hopping that accurately reproduces experimental persistent current features in mesoscopic rings.

Findings

Long-range hopping enhances electron delocalization.

Persistent current amplitude is close to that of an ordered ring.

Flux periodicity remains at hc/e in the presence of disorder.

Abstract

We show from exact calculations that a simple tight-binding Hamiltonian with diagonal disorder and long-range hopping integrals, falling off as a power $\mu$ of the inter-site separation, correctly describes the experimentally observed amplitude (close to the value of an ordered ring) and flux-periodicity ($hc/e$) of persistent currents in single-isolated-diffusive normal metal rings of mesoscopic size. Long-range hopping integrals tend to delocalize the electrons even in the presence of disorder resulting orders of magnitude enhancement of persistent current relative to earliar predictions.