All-electrical measurements of direct spin Hall effect in GaAs with Esaki diode electrodes

TL;DR

This study measures the direct spin Hall effect in lightly doped GaAs using Esaki diode contacts, analyzing bias and temperature effects to understand the contributions of skew scattering and side jump mechanisms.

Contribution

It provides the first detailed analysis of spin Hall conductivity contributions in lightly doped GaAs with Esaki diode detection, highlighting their dependence on conductivity and temperature.

Findings

Skew scattering and side jump contributions vary with channel conductivity.

Temperature influences the magnitude of the spin Hall signal.

Both mechanisms are interconnected and not fully independent of conductivity.

Abstract

We report on measurements of direct spin Hall effect in a lightly n-doped GaAs channel. As spin detecting contacts we employed highly efficient ferromagnetic Fe/(Ga,Mn)As/GaAs Esaki diode structures. We investigate bias and temperature dependence of the measured spin Hall signal and evaluate the value of total spin Hall conductivity and its dependence on channel conductivity and temperature. From the results we determine skew scattering and side jump contribution to the total spin hall conductivity and compare it with the results of experiments on higher conductive n-GaAs channels[Phys. Rev. Lett. 105,156602(2010)]. As a result we conclude that both skewness and side jump contribution cannot be fully independent on the conductivity of the channel.