Spin relaxation characteristics in Ag nanowire covered with various oxides

TL;DR

This study investigates how different oxide coatings affect spin relaxation in silver nanowires, revealing a unique enhancement with Bi2O3 likely due to interfacial effects, which could enable spin-charge conversion.

Contribution

It demonstrates that Bi2O3 coating significantly increases spin-flip probability in Ag nanowires, suggesting a novel interfacial spin relaxation mechanism beyond conventional models.

Findings

Bi2O3 increases spin-flip probability by an order of magnitude.

Spin-flip probability correlates with atomic number of oxide elements.

Interfacial Rashba effect likely contributes to enhanced spin relaxation.

Abstract

We have studied spin relaxation characteristics in a Ag nanowire covered with various oxide layers of Bi2O3, Al2O3, HfO2, MgO or AgOx by using non-local spin valve structures. The spin-flip probability, a ratio of momentum relaxation time to spin relaxation time at 10 K, exhibits a gradual increase with an atomic number of the oxide constituent elements, Mg, Al, Ag and Hf. Surprisingly the Bi2O3 capping was found to increase the probability by an order of magnitude compared with other oxide layers. This finding suggests the presence of an additional spin relaxation mechanism such as Rashba effect at the Ag/Bi2O3 interface, which cannot be explained by the simple Elliott-Yafet mechanism via phonon, impurity and surface scatterings. The Ag/Bi2O3 interface may provide functionality as a spin to charge interconversion layer.