# Chiral Quasiparticle Tunneling Between Quantum Hall Edges in Proximity with a Superconductor

## TL;DR

This paper investigates tunneling between quantum Hall edge states in a graphene Josephson junction with superconducting contacts, revealing enhanced conductance and supercurrents due to chiral quasiparticle tunneling in high magnetic fields.

## Contribution

It demonstrates supercurrent support and enhanced conductance in a graphene QH device caused by tunneling between counter-propagating edge states with superconducting contacts.

## Key findings

- Supercurrents observed up to ~2.5T magnetic field.
- Enhanced conductance over a range of magnetic fields and gate voltages.
- Tunneling between quantum Hall edge states attributed to conductance and supercurrent.

## Abstract

We study a two-terminal graphene Josephson junction with contacts shaped to form a narrow constriction, less than 100nm in length. The contacts are made from type II superconducting contacts and able to withstand magnetic fields high enough to reach the quantum Hall (QH) regime in graphene. In this regime, the device conductance is determined by edge states, plus the contribution from the constricted region. In particular, the constriction area can support supercurrents up to fields of ~2.5T. Moreover, enhanced conductance is observed through a wide range of magnetic fields and gate voltages. This additional conductance and the appearance of supercurrent is attributed to the tunneling between counter-propagating quantum Hall edge states along opposite superconducting contacts.