Electronic structure of a Josephson vortex in a SIS junction

TL;DR

This paper investigates the electronic structure of Josephson vortices in SIS junctions, revealing a distinctive two-peak local density of states that can be experimentally observed, advancing understanding of quasiparticle behavior in such systems.

Contribution

It provides a detailed theoretical analysis of the quasiparticle spectrum and local DOS of Josephson vortices using quasiclassical BdG theory, highlighting features observable by STM/STS.

Findings

Two-peak structure in local DOS for Josephson vortices

Quasiparticle spectrum characterized by inhomogeneous phase difference

Potential for experimental detection via scanning tunneling microscopy

Abstract

The Josephson vortex formed in a superconductor-insulator-superconductor (SIS) junction can affect the quantum mechanics of quasiparticles by creating an effective adiabatic potential determined by the inhomogeneous distribution of the phase difference of the order parameter along the junction. Starting from the quasiclassical version of the Bogoliubov-de Gennes (BdG) theory, we found the quasiparticle spectrum and the local density of states (DOS) both for the isolated Josephson vortex and the vortex chain. The spatially resolved DOS reveals a peculiar two-peak structure for each Josephson vortex, which can be detected experimentally using the scanning tunneling microscopy/spectroscopy techniques.