Measurement of the Spin Absorption Anisotropy in Lateral Spin Valves

TL;DR

This paper investigates how the spin absorption in ferromagnetic materials varies with spin orientation, quantifies the spin-mixing conductance in Co, CoFe, and NiFe, and suggests it is limited by Sharvin conductance rather than traditional models.

Contribution

It provides the first experimental quantification of orientation-dependent spin absorption and challenges existing models by linking spin-mixing conductance to Sharvin conductance.

Findings

Spin absorption depends on spin orientation relative to magnetization.

Quantified spin-mixing conductance in Co, CoFe, NiFe.

Indicates spin-mixing conductance is limited by Sharvin conductance.

Abstract

The spin absorption process in a ferromagnetic material depends on the spin orientation relativelyto the magnetization. Using a ferromagnet to absorb the pure spin current created within a lateralspin-valve, we evidence and quantify a sizeable orientation dependence of the spin absorption inCo, CoFe and NiFe. These experiments allow determining the spin-mixing conductance, an elusivebut fundamental parameter of the spin-dependent transport. We show that the obtained valuescannot be understood within a model considering only the Larmor, transverse decoherence and spindiffusion lengths, and rather suggest that the spin-mixing conductance is actually limited by theSharvin conductance.