Counting Statistics and Dephasing Transition in an Electronic Mach-Zehnder Interferometer

TL;DR

This paper provides experimental evidence for a dephasing phase transition in electronic Mach-Zehnder interferometers caused by non-Gaussian noise, revealing insights into full counting statistics and neutrino-oscillation analogies.

Contribution

It demonstrates the existence of a novel phase transition in electronic interferometers induced by non-Gaussian noise, supported by experimental data and physical interpretation.

Findings

Evidence of a dephasing transition in interferometer visibility

Identification of non-Gaussian noise as the transition driver

Probe of full counting statistics singularity in quantum point contact

Abstract

It was recently suggested that a novel type of phase transition may occur in the visibility of electronic Mach-Zehnder Interferometers. Here, we present experimental evidence for the existence of this transition. The transition is induced by strongly non-Gaussian noise that originates from the strong coupling of a quantum point contact to the interferometer. We provide a transparent physical picture of the effect, by exploiting a close analogy to the neutrino-oscillations of particle physics. In addition, our experiment constitutes a probe of the singularity of the elusive full counting statistics of a quantum point contact.