Quantum Hall effect in graphene with superconducting electrodes.

Rickhaus, Peter; Weiss, Markus; Marot, Laurent; Schönenberger, Christian · Nano Lett · 2012

basic_science · Level V

Where this comes from

Abstract

We have realized an integer quantum Hall system with superconducting contacts by connecting graphene to niobium electrodes. Below their upper critical field of 4 T, an integer quantum Hall effect coexists with superconductivity in the leads but with a plateau conductance that is larger than in the normal state. We ascribe this enhanced quantum Hall plateau conductance to Andreev processes at the graphene-superconductor interface leading to the formation of so-called Andreev edge-states. The enhancement depends strongly on the filling-factor and is less pronounced on the first plateau due to the special nature of the zero energy Landau level in monolayer graphene.