Detecting crossed Andreev reflection in a quantum Hall interferometer with a superconducting beam splitter

TL;DR

This paper investigates how Andreev reflection processes influence electron interference in a quantum Hall setup with a superconductor, proposing a method to detect these processes via current correlation measurements.

Contribution

It introduces a novel approach combining scattering theory and simulations to identify local and crossed Andreev reflections in quantum Hall interferometers.

Findings

Andreev processes significantly modify the HOM dip.

Charge cross correlations reveal local and crossed Andreev processes.

Simulation results support experimental detection of Andreev reflections.

Abstract

We study time-domain electron interferometry in a Hong-Ou-Mandel (HOM) geometry, where a thin superconductor between two quantum Hall systems acts as the beam splitter. By comparing the measurable current cross correlations at the interferometer outputs with those of a normal-conducting electronic HOM setup, we show that Andreev processes strongly affect the HOM dip. Using a combination of scattering theory and numerical tight-binding simulations for a graphene quantum Hall bar, we show that the change of charge cross correlations can be used to experimentally detect and characterize local and crossed Andreev processes.