On the role of electron correlation and disorder on persistent currents in isolated one-dimensional rings

TL;DR

This paper investigates how electron correlation and disorder influence persistent currents in isolated one-dimensional rings, revealing that correlation can enhance currents and induce anomalous oscillations, with results converging as ring size increases.

Contribution

It provides a detailed analysis of the combined effects of electron correlation and disorder on persistent currents in 1D rings without needing configuration averaging.

Findings

Disorder suppresses persistent currents significantly.

Electron correlation can enhance persistent currents in disordered rings.

Correlation induces kink-like structures in current, resembling anomalous Aharonov-Bohm oscillations.

Abstract

To understand the role of electron correlation and disorder on persistent currents in isolated 1D rings threaded by magnetic flux $\phi$, we study the behavior of persistent currents in aperiodic and ordered binary alloy rings. These systems may be regarded as disordered systems with well-defined long-range order so that we do not have to perform any configuration averaging of the physical quantities. We see that in the absence of interaction, disorder suppresses persistent currents by orders of magnitude and also removes its discontinuity as a function of $\phi$. As we introduce electron correlation, we get enhancement of the currents in certain disordered rings. Quite interestingly we observe that in some cases, electron correlation produces kink-like structures in the persistent current as a function of $\phi$. This may be considered as anomalous Aharonov-Bohm oscillations of the persistent current and recent experimental observations support such oscillations. We find that the persistent current converges with the size of the rings.