Spin-dependent edge-channel transport in a Si/SiGe quantum Hall system

TL;DR

This study investigates spin-dependent electron transport along edge channels in a high-mobility Si/SiGe quantum Hall system, revealing how spin orientation influences scattering and transport properties due to weak spin-orbit interaction.

Contribution

It demonstrates the spin dependence of edge-channel transport in silicon-based 2D systems, highlighting the role of Zeeman splitting and magnetic field orientation.

Findings

Suppression of scattering between spin-up and spin-down edge channels.

Enlarged Zeeman splitting switches spin orientations, promoting scattering.

Spin dependence is unique to silicon-based 2D electron systems.

Abstract

We study the edge-channel transport of electrons in a high-mobility Si/SiGe two-dimensional electron system in the quantum Hall regime. By selectively populating the spin-resolved edge channels, we observe suppression of the scattering between two edge channels with spin-up and spin-down. In contrast, when the Zeeman splitting of the spin-resolved levels is enlarged with tilting magnetic field direction, the spin orientations of both the relevant edge channels are switched to spin-down, and the inter-edge-channel scattering is strongly promoted. The evident spin dependence of the adiabatic edge-channel transport is an individual feature in silicon-based two-dimensional electron systems, originating from a weak spin-orbit interaction.