Aharonov-Bohm conductance through a single-channel quantum ring: Persistent-current blockade and zero-mode dephasing

TL;DR

This paper investigates how electron-electron interactions influence conductance in a quantum ring, revealing interaction-induced resonances and a dephasing mechanism driven by circular-current fluctuations.

Contribution

It demonstrates the persistence of interaction-induced conductance resonances and identifies a dephasing mechanism independent of interaction strength.

Findings

Conductance exhibits interaction-induced resonances with a period set by interaction strength.

Tunneling current is blocked by circular currents, affecting transport.

Dephasing rate is proportional to tunneling rate and independent of interaction strength.

Abstract

We study the effect of electron-electron interaction on transport through a tunnel-coupled single-channel ring. We find that the conductance as a function of magnetic flux shows a series of interaction-induced resonances that survive thermal averaging. The period of the series is given by the interaction strength $\alpha$. The physics behind this behavior is the blocking of the tunneling current by the circular current. The main mechanism of dephasing is due to circular-current fluctuations. The dephasing rate is proportional to the tunneling rate and does not depend on $\alpha$.