Pseudospin polarized quantum transport in monolayer graphene

Abstract

Monolayer graphene with an energy gap presents a pseudospin symmetry broken ferromagnet with a perpendicular pseudomagnetization whose direction is switched by altering the type of doping between n and p. We demonstrate an electrical current switching effect in pseudospin version of a spin valve in which two pseudoferromagnetic regions are contacted through a normal graphene region. The proposed structure exhibits a pseudomagnetoresistance, defined as the relative difference of resistances of parallel and antiparallel alignments of the pseudomagnetizations, which can be tuned to unity. This perfect pseudomagnetic switching is found to show a strong robustness with respect to increasing of the contact length, the effect which we explain in terms of an unusually long range penetration of an equilibrium pseudospin polarization into the normal region by proximity to a pseudoferromagnet. Our results reveals the potential of gapped graphene for realization of pseudospin-based nanoelectronics.