Hanbury Brown-Twiss interferometry at the $\nu=2/5$ fractional quantum Hall edge

TL;DR

This paper proposes a Hanbury Brown-Twiss interferometer for a fractional quantum Hall edge system at filling factor 2/5, analyzing two-particle interference effects and flux-dependent noise characteristics.

Contribution

It introduces a novel interferometer setup relying on two-particle interference in fractional quantum Hall systems, with analytic results for flux-dependent noise.

Findings

Analytic expression for flux-dependent noise resembling electronic HBT interferometer

Effective fractional charge e/3 appears in the noise structure

Device size influences the visibility of anyonic statistical phases

Abstract

We propose a Hanbury Brown-Twiss interferometer for a $\nu=2/5$ fractional quantum Hall edge system, in which quasiparticles tunnel between two co-propagating edge modes. In contrast to the previously studied anyonic Fabry-P\'{e}rot and Mach-Zehnder interferometers, the proposed setup relies purely on two-particle interference rather than single-particle interference. In the weak-tunneling regime, we employ a bosonized edge theory together with Keldysh perturbation theory to evaluate the cross-correlation of the tunneling currents. In the large-device limit, we obtain an analytic expression for the flux-dependent noise, whose structure closely resembles that of an electronic HBT interferometer, but with the electron charge replaced by the fractional charge $e^{\star}=e/3$ and with scaling dimensions characteristic of the fractional edge modes. In this limit, the explicit anyonic exchange phases cancel, whereas when the device size becomes comparable to the thermal length, the cross-correlation may recover a more explicit dependence on the anyonic statistical angle.