Josephson and Quasiparticle Tunneling between Anisotropically Paired Superconductors

TL;DR

This paper provides a theoretical analysis of charge transport in tunnel junctions between anisotropically paired superconductors, revealing unique features in the I-V characteristics due to anisotropic pairing effects.

Contribution

It introduces an analytical description of singular points in I-V curves for anisotropic superconductors and examines all four current components under various conditions.

Findings

Identification of characteristic singular points in I-V curves

Analytical description of electric current components

Numerical I-V curves for specific cases

Abstract

Charge transport in tunnel junctions between singlet anisotropically paired superconductors is investigated theoretically making use of the Eilenberger equations for the quasiclassical Green functions. For specularly reflecting tunnel barrier plane we have found and described analytically characteristic singular points of the I-V curves which are specific for the case of anisotropic pairing. All four terms for the electric current are examined. Two of them describe ac Josephson effect and two correspond to the quasiparticle current (the last term occurs only for a time-dependent voltage). Various momentum dependences of the order parameter in the bulk of superconductors and different crystal orientations are considered. The results of numerical calculations for the total I-V curves are presented for some particular cases.