Superconducting proximity effect on a two-dimensional Dirac electron system

Abstract

The superconducting proximity effect on two-dimensional massless Dirac electrons is usually analyzed using a simple model consisting of the Dirac Hamiltonian and an energy-independent pair potential. Although this conventional model is plausible, it is questionable whether it can fully describe the proximity effect from a superconductor. Here, we derive a more general proximity model starting from an appropriate microscopic model for the Dirac electron system in planar contact with a superconductor. The resulting model describes the proximity effect in terms of the energy-dependent pair potential and renormalization term. Within this framework, we analyze the density of states, the quasiparticle wave function, and the charge conservation of Dirac electrons. The result reveals several characteristic features of the proximity effect, which cannot be captured within the conventional model.

9 pages, 3 figures

References in corpus (12)

• Electric Field Effect in Atomically Thin Carbon Films
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Bipolar supercurrent in graphene
• Three dimensional topological invariants for time reversal invariant Hamiltonians and the three dimensional quantum spin Hall effect
• Specular Andreev reflection in graphene
• Electrically detected interferometry of Majorana fermions in a topological insulator
• Josephson effect in ballistic graphene
• Josephson Current and Multiple Andreev Reflections in Graphene SNS Junctions
• Tunneling conductance of graphene NIS junctions
• Dirac-fermions and conductance-oscillations in (s,d)-wave superconductor/normal graphene junctions
• Andreev reflection in bilayer graphene
• Quasiclassical Theory of the Josephson Effect in Ballistic Graphene Junctions

Cited by in corpus (7)

• Suppression of the overlap between Majorana fermions by orbital magnetic effects in semiconducting-superconducting nanowires
• Destructive interference of direct and crossed Andreev pairing in a system of two nanowires coupled via an s-wave superconductor
• Hard gap in a normal layer coupled to a superconductor
• Controversy over large proximity induced s wave like pairing from a d wave superconductor
• Inverse proximity effect in $s$-wave and $d$-wave superconductors coupled to topological insulators
• Josephson coupling between superconducting islands on single and bilayer graphene
• Unified Formula for Stationary Josephson Current in Planar Graphene Junctions