Electron spin interferometry using a semiconductor ring structure

TL;DR

This paper demonstrates electron spin interference in a GaAs ring structure by using optical pumping to control local magnetic fields, enabling manipulation of spin precession and interference in a semiconductor device.

Contribution

It introduces a novel semiconductor ring structure for electron spin interferometry with optical control of local magnetic fields via nuclear polarization.

Findings

Successful demonstration of spin interference in a GaAs ring.

Optical pumping modulates local magnetic fields affecting spin precession.

Potential for spin-based quantum information processing.

Abstract

A ring structure fabricated from GaAs is used to achieve interference of the net spin polarization of conduction band electrons. Optically polarized spins are split into two packets by passing through two arms of the ring in the diffusive transport regime. Optical pumping with circularly polarized light on one arm establishes dynamic nuclear polarization which acts as a local effective magnetic field on electron spins due to the hyperfine interaction. This local field causes one spin packet to precess faster than the other, thereby controlling the spin interference when the two packets are combined.