Nanomechanical detection of the spin Hall effect

TL;DR

This paper introduces a novel nanomechanical method to measure the spin Hall effect by detecting the mechanical torque caused by spin currents, providing a new way to quantify the effect and actuate nanomechanical systems.

Contribution

The paper presents a new mechanical measurement technique for the spin Hall effect based on angular momentum transfer, enabling independent quantification of the effect.

Findings

Mechanical torque due to spin currents can be detected with nanomechanical devices.

The method allows for independent measurement of the spin Hall effect.

Potential for actuating nanomechanical systems with spin currents.

Abstract

The spin Hall effect creates a spin current in response to a charge current in a material that has strong spin-orbit coupling. The size of the spin Hall effect in many materials is disputed, requiring independent measurements of the effect. We develop a novel mechanical method to measure the size of the spin Hall effect, relying on the equivalence between spin and angular momentum. The spin current carries angular momentum, so the flow of angular momentum will result in a mechanical torque on the material. We determine the size and geometry of this torque and demonstrate that it can be measured using a nanomechanical device. Our results show that measurement of the spin Hall effect in this manner is possible and also opens possibilities for actuating nanomechanical systems with spin currents.