Fine structure of the local pseudogap and Fano effect for superconducting electrons near a zigzag graphene edge

TL;DR

This paper explores the local electronic structure and Fano resonance effects near a zigzag graphene edge, revealing how these phenomena influence superconducting electron transport and Josephson current behavior.

Contribution

It introduces a model analyzing the interplay of quasiparticle states and Fano resonance effects near zigzag edges, predicting temperature-dependent Josephson current enhancements.

Findings

Temperature enhances the critical Josephson current.

Fano resonance affects local density of states near the edge.

Predicted 0-pi transitions in superconducting transport.

Abstract

Motivated by recent scanning tunneling experiments on zigzag-terminated graphene this paper investigates an interplay of evanescent and extended quasiparticle states in the local density of states (LDOS) near a zigzag edge using the Green's function of the Dirac equation. A model system is considered where the local electronic structure near the edge influences transport of both normal and superconducting electrons via a Fano resonance. In particular, the temperature enhancement of the critical Josephson current and 0-pi transitions are predicted.