Edge Channel Interference Controlled by Landau Level Filling

TL;DR

This study investigates how the visibility of Aharonov-Bohm interference in a quantum Hall Mach-Zehnder interferometer varies with the Landau level filling factor, revealing a maximum near half-integer filling and linking interference to edge channel structure.

Contribution

It demonstrates the dependence of interference visibility on the local edge channel structure and identifies a maximum near filling factor 1.5, providing new insights into quantum Hall edge physics.

Findings

Visibility peaks near filling factor 1.5

Interference depends on local edge channel structure

Three energy scales show similar filling factor dependence

Abstract

We study the visibility of Aharonov-Bohm interference in an electronic Mach-Zehnder interferometer (MZI) in the integer quantum Hall regime. The visibility is controlled by the filling factor $\nu$ and is observed only between $\nu \approx 2.0$ and 1.0, with an unexpected maximum near $\nu=1.5$. Three energy scales extracted from the temperature and voltage dependences of the visibility change in a very similar way with the filling factor, indicating that the different aspects of the interference depend sensitively on the local structure of the compressible and incompressible strips forming the quantum Hall edge channels.