Orbitronics: the Intrinsic Orbital Hall Effect in p-Doped Silicon

TL;DR

This paper predicts a dissipationless orbital Hall effect in p-doped silicon, where an electric field induces a robust orbital current, potentially detectable via Kerr effect, despite silicon's weak spin-orbit coupling.

Contribution

It demonstrates the intrinsic orbital Hall effect in silicon, showing it is robust against disorder and can occur without strong spin-orbit coupling.

Findings

Orbital Hall effect can be induced in p-doped silicon.

The effect is robust against impurity scattering.

Orbital accumulation can be detected by Kerr effect.

Abstract

The spin Hall effect depends crucially on the intrinsic spin-orbit coupling of the energy band. Because of the smaller spin-orbit coupling in silicon, the spin Hall effect is expected to be much reduced. We show that the electric field in p-doped silicon can induce a dissipationless orbital current in a fashion reminiscent of the spin Hall effect. The vertex correction due to impurity scattering vanishes and the effect is therefore robust against disorder. The orbital Hall effect can lead to the accumulation of local orbital momentum at the edge of the sample, and can be detected by the Kerr effect.