The effect of in-plane magnetic field on the spin Hall effect in Rashba-Dresselhaus system

TL;DR

This study investigates how an in-plane magnetic field influences the spin Hall effect in a Rashba-Dresselhaus 2D electron system, revealing significant tunability of spin Hall conductivity without affecting charge Hall conductivity.

Contribution

It demonstrates that the spin Hall conductivity can be significantly modulated by magnetic field direction and strength, depending on the chemical potential's position relative to the degenerate point.

Findings

Spin Hall conductivity varies by about 100% with magnetic field direction when chemical potential is between band bottom and degenerate point.

Spin Hall conductivity remains constant at e/8π when chemical potential is above the degenerate point.

In-plane magnetic field does not affect charge Hall conductivity.

Abstract

In a two-dimensional electron gas with Rashba and Dresselhaus spin-orbit couplings, there are two spin-split energy surfaces connected with a degenerate point. Both the energy surfaces and the topology of the Fermi surfaces can be varied by an in-plane magnetic field. We find that, if the chemical potential falls between the bottom of the upper band and the degenerate point, then simply by changing the direction of the magnetic field, the magnitude of the spin Hall conductivity can be varied by about 100 percent. Once the chemical potential is above the degenerate point, the spin Hall conductivity becomes the constant $e/8\pi$, independent of the magnitude and direction of the magnetic field. In addition, we find that the in-plane magnetic field exerts no influence on the charge Hall conductivity.