Interface resistance in ferromagnet/superconductor junctions

TL;DR

This paper presents a theoretical analysis of spin-polarized tunneling in ferromagnet/superconductor junctions, calculating spin and charge currents, and introduces the first calculation of excess resistance due to charge imbalance, with implications for spintronics.

Contribution

It introduces a model that accounts for spin subband splitting and impurity scattering, and calculates the excess resistance in FS contacts for the first time.

Findings

Calculated spin and charge currents as functions of voltage and polarization.

First-time calculation of excess resistance due to charge imbalance.

Implications for spin-coupled magnetoresistance and spin polarization measurement.

Abstract

Results of theoretical study of spin-polarized tunneling in ferromagnet/superconductor junctions are presented. Spin and charge currents are calculated as a function of applied voltage and spin polarization in a ferromagnet. The model takes into account the splitting of different spin subbands in a ferromagnet and impurity scattering in the contact. The excess resistance of an FS contact due to the charge-imbalance in a superconductor is calculated for the first time. The results have implications for spin-coupled magnetoresistance in ferromagnet/superconductor contacts and for measuring spin polarization in ferromagnets.