Time-dependent transport in Aharonov-Bohm interferometers

TL;DR

This paper uses a numerical approach combining self-consistent electrostatics and time-dependent quantum mechanics to analyze transport and interference in realistic quantum Hall Aharonov-Bohm interferometers, revealing conditions for maximum visibility and controllable switching.

Contribution

It introduces a combined self-consistent and time-dependent Schrödinger equation method to study transport in realistic Aharonov-Bohm interferometers under quantum Hall conditions.

Findings

Aharonov-Bohm oscillations depend on channel distance and width.

Maximum interference visibility occurs at an optimal channel separation.

Transport is suppressed at half-integer flux quanta.

Abstract

A numerical approach is employed to explain transport characteristics in realistic, quantum Hall based Aharonov-Bohm interferometers. First, the spatial distribution of incompressible strips, and thus the current channels, are obtained applying a self-consistent Thomas-Fermi method to a realistic heterostructure under quantized Hall conditions. Second, the time-dependent Schr\"odinger equation is solved for electrons injected in the current channels. Distinctive Aharonov-Bohm oscillations are found as a function of the magnetic flux. The oscillation amplitude strongly depends on the mutual distance between the transport channels and on their width. At an optimal distance the amplitude and thus the interchannel transport is maximized, which determines the maximum visibility condition. On the other hand, the transport is fully suppressed at magnetic fields corresponding to half-integer flux quanta. The results confirm the applicability of realistic Aharonov-Bohm interferometers as controllable current switches.