Nonequilibrium edge transport in quantum Hall based Josephson junctions

TL;DR

This paper investigates the unique nonequilibrium transport phenomena in quantum Hall-based Josephson junctions, revealing how edge modes influence current and can be used for spectroscopic identification of chiral edge states.

Contribution

It introduces a numerical study of out-of-equilibrium Josephson current in quantum Hall systems using Floquet-Keldysh formalism, highlighting edge mode spectroscopy.

Findings

Resonant multiple Andreev reflections enhance quasiparticle transmission.

Full current tomography enables complete spectroscopy of edge modes.

Edge-mediated transport signatures serve as hallmarks of chiral edge states.

Abstract

We study the transport properties of a voltage-biased Josephson junction where the BCS superconducting leads are coupled via the edges of a quantum Hall sample. In this scenario, an out of equilibrium Josephson current develops, which is numerically studied within the Floquet-Keldysh Green's function formalism. We particularly focus on the time-averaged current as a function of both the bias voltage and the magnetic flux threading the sample and analyze the resonant multiple Andreev reflection processes that lead to an enhancement of the quasiparticle transmission. We find that a full tomography of the dc current in the voltage-flux plane allows for a complete spectroscopy of the one-way edge modes and could be used as a hallmark of chiral edge mediated transport in these hybrid devices.