Transient quantum transport in double-dot Aharonov-Bohm interferometers

TL;DR

This paper investigates the real-time quantum dynamics of electrons in double-dot Aharonov-Bohm interferometers, revealing how coherence and transient oscillations depend on system parameters and differ from equilibrium expectations.

Contribution

It provides an exact solution to the master equation for transient quantum transport, highlighting the effects of bias, energy differences, and coupling asymmetry on coherence and current oscillations.

Findings

Coherence enhances AB oscillations in transient current.

Transient oscillations do not obey phase rigidity.

Circulating current exhibits anti-symmetric AB oscillation.

Abstract

Real-time nonequilibrium quantum dynamics of electrons in double-dot Aharonov-Bohm (AB) interferometers is studied using an exact solution of the master equation. The building of the coherence between the two electronic paths shows up via the time-dependent amplitude of the AB oscillations in the transient transport current, and can be enhanced by varying the applied bias on the leads, the on-site energy difference between the dots and the asymmetry of the coupling of the dots to the leads. The transient oscillations of the transport current do not obey phase rigidity. The circulating current has an anti-symmetric AB oscillation in the flux. The non-degeneracy of the on-site energies and the finite bias cause the occupation in each dot to have an arbitrary flux dependence as the coupling asymmetry is varied.