Transport through ferromagnet/superconductor interfaces

TL;DR

This paper investigates how spin-polarized electron transport and Zeeman-splitting affect the differential resistance asymmetries in ferromagnet/superconductor interfaces, revealing the influence of magnetization orientation.

Contribution

It demonstrates the role of spin polarization and magnetic field orientation in the resistance asymmetries at ferromagnet/superconductor interfaces.

Findings

Asymmetries depend on spin-polarized transport and Zeeman-splitting.

Magnetization orientation influences the resistance asymmetries.

Magnetic field from the ferromagnet affects quasiparticle density of states.

Abstract

The differential resistance of submicron-size ferromagnet/superconductor interface structures shows asymmetries as a function of the current through the ferromagnet/superconductor interface. These asymmetries are a consequence of spin-polarized electron transport from the ferromagnet to the superconductor, coupled with the Zeeman-splitting of the superconducting quasiparticle density of states. They are sensitive to the orientation of the magnetization of the ferromagnet, as the magnetic field required to spin-split the quasiparticle density of states can be provided by the ferromagnetic element itself.