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.
@article{arxiv.cond-mat/0303448,
title = {Spatial Imaging of Magnetically Patterned Nuclear Spins in GaAs},
author = {J. Stephens and R. K. Kawakami and J. Berezovsky and M. Hanson and D. P. Shepherd and A. C. Gossard and D. D. Awschalom},
journal= {arXiv preprint arXiv:cond-mat/0303448},
year = {2009}
}
Comments
Submitted to Physical Review B Rapid Communications. 18 pages, 4 figures