Andreev Reflection In Quantum Anomalous Hall Effect-superconductor Junction

Andreev reflection is an important transport process. The Andreev reflection occurs near the interface of a conductor and a superconductor, in which an incident electron from the metallic side is reflected as a hole and a Cooper pair is created in the superconductor. The Andreev reflection has long served as a useful probe for spin-polarized currents. The Andreev reflection appears to be particularly suited to study edge state scattering in topological insulators and its heterostructures.Although the Andreev reflection has been extensively investigated in quantum dot,graphene, quantum wire and quantum spin Hall effect-superconductor junction. But, no one has investigated the Andreev reflection in quantum anomalous Hall effect-superconductor junction. In this article, we investigated the Andreev reflection in quantum anomalous Hall effect-superconductor junction by the nonequilibrium Green’s function.(1) we investigated the Andreev reflection in quantum anomalous Hall effect of single channel boundary exists-superconductor junction. We show that when the Hg Te/Cd Te quantum well is doped with magnetic Mn atoms, the quantum anomalous Hall effect can be realized. we calculated the Andreev reflection coefficient in two-dimensional heterojunctions formed by a superconductor in contact with a Hg Te/Cd Te quantum well is doped with magnetic Mn atoms.We found that the Andreev reflection coefficient is equal to zero.(2) we investigated the Andreev reflection in quantum anomalous Hall effect of dual channel boundary exists-superconductor junction. We calculated the Andreev reflection coefficient in two-dimensional heterojunctions formed by a superconductor in contact with a graphene which have Rashba spin-orbit coupling and exchange field. We found that the Andreev reflection coefficient is not completely suppressed, a graphene/superconductor interface may reflect an incident electron from the metal as a positively charged hole with opposite spin, the Andreev reflection coefficient isn’t equal to zero.