Observation of the inverse spin Hall effect in silicon

TL;DR

This paper reports the first observation of the inverse spin Hall effect in silicon at room temperature, demonstrating silicon's potential as a spin-current detector despite its weak spin-orbit interaction.

Contribution

The study provides the first experimental evidence of the inverse spin Hall effect in silicon, a fundamental semiconductor, at room temperature.

Findings

Inverse spin Hall effect observed in silicon at room temperature.

Spin Hall angle in p-type silicon is approximately 0.0001.

Silicon can serve as a spin-current detector despite weak spin-orbit coupling.

Abstract

The spin-orbit interaction in a solid couples the spin of an electron to its momentum. This coupling gives rise to mutual conversion between spin and charge currents: the direct and inverse spin Hall effects. The spin Hall effects have been observed in metals and semiconductors. However, the spin/charge conversion has not been realized in one of the most fundamental semiconductors, silicon, where accessing the spin Hall effects has been believed to be difficult because of its very weak spin-orbit interaction. Here we report observation of the inverse spin Hall effect in silicon at room temperature. The spin/charge current conversion efficiency, the spin Hall angle, is obtained as 0.0001 for a p-type silicon film. In spite of the small spin Hall angle, we found a clear electric voltage due to the inverse spin Hall effect in the p-Si film, demonstrating that silicon can be used as a spin-current detector.