Semiclassical theory of persistent current fluctuations in ballistic chaotic rings

TL;DR

This paper develops a semiclassical theory to analyze non-Gaussian fluctuations of persistent currents in ballistic chaotic rings, accounting for Ehrenfest time effects, revealing enhanced fluctuations at finite Ehrenfest times.

Contribution

It introduces a semiclassical calculation of the leading non-Gaussian correction for persistent current fluctuations, including Ehrenfest time dependence, in ballistic chaotic mesoscopic rings.

Findings

Non-Gaussian fluctuations are present in persistent currents.

Ehrenfest time enhances non-Gaussian fluctuations.

The approach applies to ballistic chaotic systems.

Abstract

The persistent current in a mesoscopic ring has a Gaussian distribution with small non-Gaussian corrections. Here we report a semiclassical calculation of the leading non-Gaussian correction, which is described by the three-point correlation function. The semiclassical approach is applicable to systems in which the electron dynamics is ballistic and chaotic, and includes the dependence on the Ehrenfest time. At small but finite Ehrenfest times, the non-Gaussian fluctuations are enhanced with respect to the limit of zero Ehrenfest time.