Observation of spin-selective tunneling in SiGe nanocrystals

TL;DR

This paper reports the experimental and theoretical observation of spin-selective hole tunneling in SiGe nanocrystals, driven by magnetic field effects and spin-orbit interaction, without requiring ferromagnetic contacts.

Contribution

It demonstrates a novel mechanism for spin selectivity in semiconductor nanostructures relying on orbital effects and spin-orbit coupling, expanding possibilities for spintronic devices.

Findings

Spin-selective tunneling observed in SiGe nanocrystals.

Spin selectivity arises from orbital magnetic effects combined with spin-orbit interaction.

Effect can be generalized to other semiconductor quantum-dot systems.

Abstract

Spin-selective tunneling of holes in SiGe nanocrystals contacted by normal-metal leads is reported. The spin selectivity arises from an interplay of the orbital effect of the magnetic field with the strong spin-orbit interaction present in the valence band of the semiconductor. We demonstrate both experimentally and theoretically that spin-selective tunneling in semiconductor nanostructures can be achieved without the use of ferromagnetic contacts. The reported effect, which relies on mixing the light and heavy holes, should be observable in a broad class of quantum-dot systems formed in semiconductors with a degenerate valence band.