Gate-Control of Spin Precession in Quantum Hall Edge States

TL;DR

This paper demonstrates electrical control of spin precession in quantum Hall edge states, enabling a spin-FET device without ferromagnetic materials, by manipulating electron trajectories and spin-orbit interactions.

Contribution

It introduces a novel all-electrical spin control method in quantum Hall edge states, realizing a spin-FET and interpreting it as a spin interferometer.

Findings

Spin precession is triggered at a gate corner due to electron orbital turns.

Spin phase is controlled by edge-state electron velocity via gate bias.

A spin-FET device is realized without ferromagnetic materials.

Abstract

Electrical control and detection of spin precession are experimentally demonstrated by using spin-resolved edge states in the integer quantum Hall regime. Spin precession is triggered at a corner of a biased metal gate, where electron orbital motion makes a sharp turn leading to a nonadiabatic change in the effective magnetic field via spin-orbit interaction. The phase of precession is controlled by the group velocity of edge-state electrons tuned by gate bias voltage: A spin-FET device is thus realized by all-electrical means, without invoking ferromagnetic material. The effect is also interpreted in terms of a Mach-Zehnder-type spin interferometer.