Fabry-P\'erot interferometry with stochastic anyonic sources

TL;DR

This paper studies how stochastic injection of Laughlin quasiparticles in a Fabry-Pérot interferometer reveals their anyonic exchange statistics through interference patterns, noise oscillations, and universal Fano factors.

Contribution

It introduces a novel approach to detect anyonic exchange phases via stochastic quasiparticle injection and interference in a fractional quantum Hall interferometer.

Findings

Effective Aharonov-Bohm phase includes an exchange phase contribution.

AB oscillations in tunneling current noise reveal exchange phase.

Universal Fano factor exhibits power-law scaling and phase shifts.

Abstract

We investigate the interference of Laughlin quasiparticles (QPs) in the fractional quantum Hall regime that are stochastically injected into a Fabry-P\'erot interferometer. We find that the effective Aharonov-Bohm (AB) phase accumulated along the interferometer loop acquires an additional contribution of $\sin(2\pi\lambda)/2$ per QP present on it, where $\pi\lambda$ is the QP exchange phase. This contribution originates from time-domain braiding processes associated with injected QPs passing the interferometer quantum point contacts. In the limit of symmetric QP injection, the tunneling current noise exhibits AB oscillations as a function of the total injected current, providing access to the exchange phase $\pi\lambda$. In the regime of large total injection, we identify a universal Fano factor that displays power-law scaling and a characteristic phase shift reflecting real-space QP braiding along the interferometer edges. These results are relevant for accessing anyonic exchange statistics in mesoscopic interferometers.