Microscopic theory of the proximity effect in superconductor-graphene nanostructures

作者：Burset P^*; Yeyati A Levy; Martin Rodero A

来源：Physical Review B, 2008, 77(20): 205425.

DOI：10.1103/PhysRevB.77.205425

We present a theoretical analysis of the proximity effect at a,graphene-superconductor interface. We use a tight-binding model for the electronic states in this system, which allows us to describe the interface at the microscopic level. Two different interface models are proposed: one in which the superconductor induces a finite pairing in the graphene regions underneath, thus maintaining the honeycomb structure at the interface and one that assumes that the graphene layer is directly coupled to a bulk superconducting electrode. We show that properties such as the Andreev reflection probability and its channel decomposition critically depend on the model used to describe the interface. We also study the proximity effect on the local density of states on the graphene. For finite layers, we analyze the induced minigap and how it is reduced when the length of the layer increases. The results for the local density of states profiles for finite and semi-infinite layers are presented.

• 出版日期2008-5