Abrikosov vortex nucleation and its detrimental effect on superconducting spin pumping in Pt/Nb/Ni80Fe20/Nb/Pt proximity structures

TL;DR

This study investigates how Abrikosov vortex formation in superconducting heterostructures under oblique magnetic fields impairs spin pumping efficiency, revealing the impact of vortex nucleation on superconducting spintronic devices.

Contribution

It demonstrates the detrimental effect of vortex nucleation on superconducting spin pumping in Pt/Nb/Ni80Fe20 structures under oblique magnetic fields, linking vortex formation to suppression of superconducting spin transport.

Findings

Spin pumping efficiency decreases with increasing out-of-plane field angle.

Vortex nucleation correlates with the suppression of superconductivity.

Superconducting volume becomes normal due to vortex formation at high field angles.

Abstract

We report Abrikosov vortex nucleation in Pt/Nb/Ni80Fe20/Nb/Pt proximity-coupled structures under oblique ferromagnetic resonance (FMR) that turns out to be detrimental to superconducting spin pumping. By measuring an out-of-plane field-angle {\theta}H dependence and comparison with Pt-absent control samples, we show that as {\theta}H increases, the degree of enhancement (suppression) of spin pumping efficiency in the superconducting state for the Pt-present (Pt-absent) sample diminishes and it reverts to the normal state value at {\theta}H = 90{\deg}. This can be explained in terms of a substantial out-of-plane component of the resonance field for the Ni80Fe20 layer (with in-plane magnetization anisotropy and high aspect ratio) that approaches the upper critical field of the Nb, turning a large fraction of the singlet superconductor volume into the normal state.