Spatial Imaging of Magnetically Patterned Nuclear Spins in GaAs

TL;DR

This paper demonstrates a method to spatially image and engineer nuclear spin polarization patterns in GaAs using ferromagnetic imprinting and Kerr microscopy, revealing large effective field gradients for spin landscape control.

Contribution

It introduces a novel approach combining ferromagnetic imprinting with high-resolution Kerr microscopy to spatially image and manipulate nuclear spins in GaAs.

Findings

Nuclear polarization varies significantly near magnetic mesas.

Large effective field gradients (~10^4 T/m) are observed.

The technique enables flexible lateral engineering of spin landscapes.

Abstract

We exploit ferromagnetic imprinting to create complex laterally defined regions of nuclear spin polarization in lithographically patterned MnAs/GaAs epilayers grown by molecular beam epitaxy (MBE). A time-resolved Kerr rotation microscope with approximately 1 micron spatial resolution uses electron spin precession to directly image the GaAs nuclear polarization. These measurements indicate that the polarization varies from a maximum under magnetic mesas to zero several microns from the mesa perimeter, resulting in large (10**4 T/m) effective field gradients. The results reveal a flexible scheme for lateral engineering of spin-dependent energy landscapes in the solid state.