Different steady states for spin currents in noncollinear multilayers

TL;DR

This paper identifies two distinct steady states for spin current transport in noncollinear magnetic multilayers, highlighting differences in spin current behavior and their implications for magnetic reversal mechanisms.

Contribution

It introduces a new steady state model where spin torque results from transverse spin accumulation, contrasting with the conventional discontinuity model.

Findings

Two steady states with different spin current behaviors

The new state involves spin accumulation transverse to magnetization

Experimental distinctions between states are proposed

Abstract

We find there are at least two different steady states for transport across noncollinear magnetic multilayers. In the conventional one there is a discontinuity in the spin current across the interfaces which has been identified as the source of current induced magnetic reversal; in the one advocated herein the spin torque arises from the spin accumulation transverse to the magnetization of a magnetic layer. These two states have quite different attributes which should be discerned by current experiments.