The Behavior of Electronic Interferometers in the Non-Linear Regime

TL;DR

This paper theoretically explores how current oscillations in an electronic Mach-Zehnder interferometer behave under high bias, revealing a lobe pattern and phase rigidity linked to many-body quantum effects.

Contribution

It introduces a theoretical explanation for the observed lobe pattern and phase rigidity in MZI interference visibility at high bias, highlighting many-body quantum phenomena.

Findings

Visibility exhibits a bias-dependent lobe pattern.

Pattern period is proportional to average path length.

Interference phase shows rigidity independent of path difference.

Abstract

We investigate theoretically the behavior of the current oscillations in an electronic Mach-Zehnder interferometer (MZI) as a function of its source bias. Recently, The MZI interference visibility showed an unexplained lobe pattern behavior with a peculiar phase rigidity. Moreover, the effect did not depend on the MZI paths difference. We argue that these effects may be a new many-body manifestation of particle-wave duality of quantum mechanics. When biasing the interferometer sources beyond the linear response regime, quantum shot-noise (a particle phenomena) must affect the interference pattern of the electrons that creates it, as a result from a simple invariance argument. An approximate solution of the interacting Hamiltonian indeed shows that the interference visibility has a lobe pattern with applied bias with a period proportional to the average path length and independent of the paths difference, together with a phase rigidity.