Solution of a model for the two-channel electronic Mach-Zehnder interferometer

TL;DR

This paper develops an exact theoretical model for electronic Mach-Zehnder interferometers using bosonization and refermionization, providing precise conductance predictions and insights into dephasing and non-equilibrium transport.

Contribution

It introduces a non-perturbative, exact analytic approach to model electron tunneling and transport in quantum Hall edge state interferometers, advancing beyond previous approximate methods.

Findings

Derived an exact formula for differential conductance at equal arm lengths.

Provided numerically exact results for unequal arm interferometers.

Compared theoretical predictions with experimental observations.

Abstract

We develop the theory of electronic Mach-Zehnder interferometers built from quantum Hall edge states at Landau level filling factor \nu = 2, which have been investigated in a series of recent experiments and theoretical studies. We show that a detailed treatment of dephasing and non-equlibrium transport is made possible by using bosonization combined with refermionization to study a model in which interactions between electrons are short-range. In particular, this approach allows a non-perturbative treatment of electron tunneling at the quantum point contacts that act as beam-splitters. We find an exact analytic expression at arbitrary tunneling strength for the differential conductance of an interferometer with arms of equal length, and obtain numerically exact results for an interferometer with unequal arms. We compare these results with previous perturbative and approximate ones, and with observations.