Coupled Electron-hole States at Normal-Superconductor Interface of Strained Graphene

Abstract

Graphene is a promising material for nanoscale applications due to its exceptional electronic, thermal and mechanical properties. It has been shown recently that the electronic and thermal properties of Graphene can be tuned significantly by engineering strain. Especially the strain field may couple to the electronic degree of freedom as it does with the vector potential. A uniformly varying strain field could create an effective gauge field, which leads to a constant pseudo-magnetic field. Recent studies have shown the feasibility of achieving a constant pseudo magnetic field in Graphene nanoribbons leading to pseudo Landau level quantization. In this work electronic properties of strained Graphene layer with pseudo Landau levels is studied in the presence of a superconducting contact. It is demonstrated that the existence of electron-hole coupled states due to the injection of cooper pairs in to the superconductor.