Anomalous spin Hall effects in Dresselhaus (110) quantum wells

TL;DR

This paper investigates anomalous intrinsic spin Hall effects in Dresselhaus (110) quantum wells, revealing unique spin accumulation behaviors and the influence of Rashba coupling on in-plane spin separation.

Contribution

It uncovers novel intrinsic spin Hall effects in Dresselhaus (110) quantum wells, including bias-independent spin accumulation signs and the role of Rashba coupling in in-plane spin separation.

Findings

Out-of-plane spin accumulation sign remains unchanged upon bias reversal.

Bias reversal distinguishes different contributions to spin Hall accumulation.

Weak Rashba coupling induces a new in-plane spin Hall effect.

Abstract

Anomalous spin Hall effects that belong to the intrinsic type in Dresselhaus (110) quantum wells are discussed. For the out-of-plane spin component, antisymmetric current-induced spin polarization induces opposite spin Hall accumulation, even though there is no spin-orbit force due to Dresselhaus (110) coupling. A surprising feature of this spin Hall induction is that the spin accumulation sign does not change upon bias reversal. Contribution to the spin Hall accumulation from the spin Hall induction and the spin deviation due to intrinsic spin-orbit force as well as extrinsic spin scattering, can be straightforwardly distinguished simply by reversing the bias. For the inplane component, inclusion of a weak Rashba coupling leads to a new type of $S_y$ intrinsic spin Hall effect solely due to spin-orbit-force-driven spin separation.