Spin transport in a graphene normal-superconductor junction in the quantum Hall regime

Abstract

In graphene-superconductor heterostructures, superconductivity and the quantum Hall effect may coexist for an experimentally accessible range of magnetic fields. When the graphene edge states are coupled to a superconductor in the presence of a Zeeman field, the charge carriers with one spin projection get transmitted while the ones with the opposite spin projection get reflected within a certain energy region. This spin-filtering effect is a consequence of the interplay between specular Andreev reflections and Andreev retro-reflections. While the edge termination of graphene and the geometrical details do matter for the charge conductance, they have little effect on the spin polarization of the charge carriers.