Effects of screened Coulomb interaction on spin transfer torque

TL;DR

This paper investigates how electron-electron interactions and Coulomb screening influence spin transfer torque and spin mixing conductance at magnetic interfaces, reconciling theoretical predictions with experimental observations.

Contribution

It introduces a model incorporating Coulomb screening effects to accurately describe the impact of electron-electron interactions on spin mixing conductance.

Findings

Screening effects modify the electron-electron interaction at interfaces.

The model explains both increases and decreases in spin mixing conductance.

Results align with experimental data on magnetic multilayers.

Abstract

In a magnetic multilayer, magnetizations can be manipulated by spin transfer torque. Both spin transfer torque and its reciprocal effect, spin pumping, are governed by spin mixing conductance. The magnitude of spin mixing conductance at the interface of nearly magnetic metal has been theoretically shown to be enhanced by electron-electron interaction. However, experiments show both increasing and decreasing values of spin mixing conductance for metals with larger electron-electron interaction. Here we take into account the effect of electron-electron interaction on the screening of the Coulomb interaction at the magnetic interface to correctly describe the experiment.