Evolution of the spin Hall effect in Pt nanowires: Size and temperature effects

TL;DR

This study investigates how the spin Hall effect in platinum nanowires varies with size and temperature, revealing that bulk scattering and spin diffusion length significantly influence spin accumulation and conductivity.

Contribution

It provides new insights into the size and temperature dependence of the spin Hall effect in Pt nanowires, highlighting the role of bulk scattering and spin diffusion length.

Findings

Spin accumulation decreases as Pt thickness exceeds the spin diffusion length.

Spin Hall conductivity varies with temperature, indicating dominant scattering mechanisms.

Bulk scattering inside Pt primarily drives the spin Hall effect in the studied regime.

Abstract

We have studied the evolution of the Spin Hall Effect in the regime where the material size responsible for the spin accumulation is either smaller or larger than the spin diffusion length. Lateral spin valve structures with Pt insertions were successfully used to measure the spin absorption efficiency as well as the spin accumulation in Pt induced through the spin Hall effect. Under a constant applied current the results show a decrease of the spin accumulation signal is more pronounced as the Pt thickness exceeds the spin diffusion length. This implies that the spin accumulation originates from bulk scattering inside the Pt wire and the spin diffusion length limits the SHE. We have also analyzed the temperature variation of the spin hall conductivity to identify the dominant scattering mechanism.