Spin-current vortices in current-perpendicular-to-plane nanoconstricted spin-valves

TL;DR

This paper numerically investigates spin-dependent transport in nanoconstricted spin-valves, revealing unexpected spin-current vortices and highlighting the influence of geometry on magnetoresistance and spin-transfer torque.

Contribution

It introduces a finite element method for solving spin diffusion equations in complex geometries, uncovering novel spin-current vortex phenomena.

Findings

Discovery of spin-current vortices near nanoconstrictions

Geometry significantly affects magnetoresistance and spin-transfer torque

Numerical solutions account for spin-flip and spin-transfer effects

Abstract

The charge and spin diffusion equations taking into account spin-flip and spin-transfer torque were numerically solved using a finite element method in complex non-collinear geometry with strongly inhomogeneous current flow. As an illustration, spin-dependent transport through a non-magnetic nanoconstriction separating two magnetic layers was investigated. Unexpected results such as vortices of spin-currents in the vicinity of the nanoconstriction were obtained. The angular variations of magnetoresistance and spin-transfer torque are strongly influenced by the structure geometry.