Mechanisms of Andreev reflection in quantum Hall graphene
Antonio L. R. Manesco, I. M. Flór, Chun-Xiao Liu, Anton Akhmerov
Abstract
We simulate a hybrid superconductor-graphene device in the quantum Hall regime to identify the origin of downstream resistance oscillations in a recent experiment [Zhao et al., Nature Physics 16, (2020)]. In addition to the previously studied Mach-Zehnder interference between the valley-polarized edge states, we consider disorder-induced scattering, and the appearance of the counter-propagating states generated by the interface density mismatch. Comparing our results with the experiment, we conclude that the observed oscillations are induced by the interfacial disorder, and that lattice-matched superconductors are necessary to observe the alternative ballistic effects.
Topics & Concepts
Andreev reflectionCondensed matter physicsGrapheneSuperconductivityPhysicsQuantum Hall effectScatteringQuantumLattice (music)Quantum mechanicsMagnetic fieldAcousticsGraphene research and applicationsQuantum and electron transport phenomenaTopological Materials and Phenomena