Channel Interference in a Quasi Ballistic Aharonov-Bohm Experiment

TL;DR

This paper reports on experiments observing magnetoconductance oscillations in a 2DEG ring, revealing phase shifts and mode energy spacings, supported by a theoretical model with random phase shifts.

Contribution

It introduces a new experimental setup for studying channel interference and provides a theoretical model explaining observed phase shifts in electron wave transmission.

Findings

Magnetoconductance oscillations observed in a 2DEG ring.

Phase of Aharonov-Bohm signal alternates with gate voltage.

Fourier analysis reveals energy spacing between modes.

Abstract

New experiments are presented on the transmission of electron waves through a 2DEG (2 dimensional electron gas) ring with a gate on top of one of the branches. Magnetoconductance oscillations are observed, and the phase of the Aharanov-Bohm signal alternates between 0 and pi as the gate voltage is scanned. A Fourier transform of the data reveals a dominant period in the voltage which corresponds to the energy spacing between successive transverse modes.A theoretical model including random phase shifts between successive modes reproduces the essential features of the experiment.