Spin Aharonov-Bohm effect and topological spin transistor

TL;DR

This paper introduces a novel nonlocal spin control mechanism using the spin Aharonov-Bohm effect in quantum spin Hall insulators, enabling a topological spin transistor operated solely by magnetic flux without electromagnetic forces.

Contribution

It proposes the first realization of a spin Aharonov-Bohm effect in quantum spin Hall insulators, enabling flux-controlled spin manipulation for topological spintronics devices.

Findings

Demonstrates flux-controlled spin rotation without electromagnetic forces.

Proposes a topological spin transistor based on quantum spin Hall edge states.

Shows the device's operation is independent of sample details.

Abstract

Ever since its discovery, the electron spin has only been measured or manipulated through the application of an electromagnetic force acting on the associated magnetic moment. In this work, we propose a spin Aharonov-Bohm effect in which the electron spin is controlled by a magnetic flux while no electromagnetic field is acting on the electron. Such a nonlocal spin manipulation is realized in an Aharonov-Bohm ring made from the recently discovered quantum spin Hall insulator, by taking advantage of the defining property of the quantum spin Hall edge states: the one-to-one correspondence between spin polarization and direction of propagation. The proposed setup can be used to realize a new spintronics device, the topological spin transistor, in which the spin rotation is completely controlled by a magnetic flux of hc/2e, independently of the details of the sample.