Detecting entangled states in graphene via crossed Andreev reflection

TL;DR

This paper investigates how the unique band structure of graphene enables the detection of entangled states through crossed Andreev reflection, with tunable shot noise correlations indicating entanglement.

Contribution

It introduces a novel approach to detect entanglement in graphene by analyzing shot noise cross-correlations influenced by specular crossed Andreev reflection.

Findings

Positive shot noise cross-correlations indicate entanglement.

Gate voltage can tune the sign of cross-correlations.

Unique graphene band structure affects Andreev reflection behavior.

Abstract

Shot noise cross-correlations across single layer graphene structures are calculated with insulators separating a superconducting region. A new feature of specular crossed Andreev reflection comes into play due to the unique band structure of graphene. This gives rise to a rich structure in the states of the electric current flowing across the graphene sheet. We identified a parametric regime where {\em positive} shot noise cross-correlations of the current appear signifying entanglement. In contrast to previous proposals the sign of the cross-correlations can be easily tuned by the application of a gate voltage.