Visibility of current and shot noise in electrical Mach-Zehnder and Hanbury Brown Twiss interferometers

TL;DR

This paper compares the visibility of current and shot noise in electrical analogs of optical Mach-Zehnder and Hanbury Brown Twiss interferometers, highlighting differences in their response to temperature, voltage, and dephasing.

Contribution

It provides a detailed comparison of shot noise visibility in amplitude and intensity interferometers, revealing their similar and differing behaviors under various conditions.

Findings

Shot noise visibility in Hanbury Brown Twiss interferometer is similar to the first harmonic of Mach-Zehnder.

Second harmonic shot noise in Mach-Zehnder decreases rapidly with temperature and dephasing.

Comparison highlights fundamental differences between amplitude and intensity interferometers.

Abstract

We investigate the visibility of the current and shot-noise correlations of electrical analogs of the optical Mach-Zehnder interferometer and the Hanbury Brown Twiss interferometer. The electrical analogs are discussed in conductors subject to high magnetic fields where electron motion is along edge states. The transport quantities are modulated with the help of an Aharonov-Bohm flux. We discuss the conductance (current) visibility and shot noise visibility as a function of temperature and applied voltage. Dephasing is introduced with the help of fictitious voltage probes. Comparison of these two interferometers is of interest since the Mach-Zehnder interferometer is an amplitude (single-particle) interferometer whereas the Hanbury Brown Twiss interferometer is an intensity (two-particle) interferometer. A direct comparison is only possible for the shot noise of the two interferometers. We find that the visibility of shot noise correlations of the Hanbury Brown Twiss interferometer as function of temperature, voltage or dephasing, is qualitatively similar to the visibility of the first harmonic of the shot noise correlation of the Mach-Zehnder interferometer. In contrast, the second harmonic of the shot noise visibility of the Mach-Zehnder interferometer decreases much more rapidly with increasing temperature, voltage or dephasing rate.