Andreev magneto-interferometry in topological hybrid junctions

TL;DR

This paper studies how superconducting proximity effects influence quantum Hall edge states in graphene-based junctions, revealing conductance peaks and interference phenomena that could enable tunable control of topological edge channels.

Contribution

It provides a theoretical analysis of charge conductance in QH/S/QH junctions, predicting interference-induced conductance peaks and offering insights into topological edge state manipulation.

Findings

Conductance peaks at integer Landau level fillings

Quantum interference effects at QH/S interfaces

Potential for tunable edge state partitioning

Abstract

We investigate the influence of the superconducting (S) proximity effect in the quantum Hall (QH) regime by computing the charge conductance flowing through a graphene-based QH/S/QH junction. This situation offers the exciting possibility of studying the fate of topological edge states when they experience tunneling processes through the superconductor. We predict the appearance of conductance peaks at integer values of the Landau level filling factor, as a consequence of the quantum interferences taking place at the junction, and provide a semiclassical analysis allowing for a natural interpretation of these interferences in terms of electron and hole trajectories propagating along the QH/S interfaces. Our results suggest that non-trivial junctions between topologically distinct phases could offer a highly tunable means of partitioning the flow of edge states.