Loss and decoherence at the quantum Hall - superconductor interface

TL;DR

This study investigates Andreev conversion at the superconductor-graphene interface in the quantum Hall regime, revealing unexpected temperature and magnetic field dependencies that could inform future hybrid device engineering.

Contribution

It provides a systematic analysis of Andreev conversion behavior in quantum Hall-superconductor interfaces, highlighting the role of vortices and decoupled dependencies on temperature and magnetic field.

Findings

Andreev conversion probability shows decoupled temperature and magnetic field dependence.

Superconducting vortices' normal cores influence electron absorption and dephasing.

Results suggest pathways for designing hybrid quantum devices.

Abstract

We perform a systematic study of Andreev conversion at the interface between a superconductor and graphene in the quantum Hall (QH) regime. We find that the probability of Andreev conversion from electrons to holes follows an unexpected but clear trend: the dependencies on temperature and magnetic field are nearly decoupled. We discuss these trends and the role of the superconducting vortices, whose normal cores could both absorb and dephase the individual electrons in a QH edge. Our study may pave the road to engineering future generation of hybrid devices for exploiting superconductivity proximity in chiral channels.