Electrical probing of the spin conductance of mesoscopic cavities

TL;DR

This paper studies how spin currents in mesoscopic cavities with spin-orbit coupling can generate measurable charge signals, enabling electrical determination of spin conductance through the inverse spin Hall effect.

Contribution

It introduces a method to extract spin conductance from electrical measurements in mesoscopic cavities and analyzes its universal fluctuations using random matrix theory.

Findings

Spin conductance fluctuates universally around zero.

Pure spin currents can generate measurable charge signals.

Proposes experimental setups for spin to charge conversion.

Abstract

We investigate spin-dependent transport in three--terminal mesoscopic cavities with spin--orbit coupling. Focusing on the inverse spin Hall effect, we show how injecting a pure spin current or a polarized current from one terminal generates additional charge current and/or voltage across the two output terminals. This allows to extract the spin conductance of the cavity from two purely electrical measurements on the output. We use random matrix theory to show that the spin conductance of chaotic ballistic cavities fluctuates universally about zero mesoscopic average and describe experimental implementations of mesoscopic spin to charge current converters.