Local control of spin flow in weak magnetic fields

TL;DR

This paper shows how optical illumination and weak magnetic fields can control spin transport in n-type GaAs, enabling manipulation of spin diffusion and flow through optical and magnetic means.

Contribution

It introduces a method to manipulate spin flow in GaAs using optical power and weak magnetic fields, demonstrated through spin imaging and Hanle measurements.

Findings

Optical spin pumping expands the spin diffusion profile.

Weak transverse magnetic fields significantly increase spin flow.

Spin transport can be controlled by light intensity and magnetic fields.

Abstract

We demonstrate that optical illumination strongly influences spin transport in n-type GaAs. Specifically, increasing the power density of optical spin pumping results in a significant expansion of the spin diffusion profile. A further means of manipulation is the application of a weak transverse magnetic field, which strongly increases spin flow out of the excitation spot. These effects are directly monitored in spin imaging experiments and spatially resolved Hanle measurements.