Spin Hall noise

TL;DR

This paper investigates the thermal fluctuations of pure spin currents in a platinum film on yttrium iron garnet, using voltage noise measurements to explore spin Hall effects and magnetoresistance.

Contribution

It provides a microscopic model linking voltage noise, spin current fluctuations, and the inverse spin Hall effect in a spin Hall noise context.

Findings

Voltage noise aligns with fluctuation dissipation theorem and SMR.

Angular dependence of noise explained by spin current fluctuations.

Microscopic description of spin Hall noise presented.

Abstract

We measure the low-frequency thermal fluctuations of pure spin current in a Platinum film deposited on yttrium iron garnet via the inverse spin Hall effect (ISHE)-mediated voltage noise as a function of the angle $\alpha$ between the magnetization and the transport direction. The results are consistent with the fluctuation dissipation theorem in terms of the recently discovered spin Hall magnetoresistance (SMR). We present a microscopic description of the $\alpha$ dependence of the voltage noise in terms of spin current fluctuations and ISHE.