Ambipolar spin diffusion and D'yakonov-Perel' spin relaxation in GaAs quantum wells
Issue Date
2009-03Author
Zhao, Hui
Mower, Matt
Vignale, G.
Publisher
American Physical Society
Type
Other
Version
http://arxiv.org/abs/0903.4931v1
Metadata
Show full item recordAbstract
We report theoretical and experimental studies of ambipolar spin diffusion in a semiconductor. A circularly polarized laser pulse is used to excite spin-polarized carriers in a GaAs multiple quantum-well sample at 80 K. Diffusion of electron and spin densities is simultaneously measured using a spatially and temporally resolved pump-probe technique. Two regimes of diffusion for spin-polarized electrons are observed. Initially, the rate of spin diffusion is similar to that of density diffusion and is controlled by the ambipolar diffusion coefficient. At later times, the spin diffusion slows down considerably relative to the density diffusion and appears to be controlled by a nonconstant (decreasing) spin-diffusion coefficient. We suggest that the long-time behavior of the spin density can be understood in terms of an inhomogeneous spin-relaxation rate, which grows with decreasing density. The behavior of the spin-relaxation rate is consistent with a model of D'yakonov-Perel' relaxation limited by the Coulomb scattering between carriers.
Description
Permissions were not obtained for sharing the full text of this article. Full text available from the American Physical Society and from arXiv. See links in this record.
Collections
Citation
Hui Zhao, M. Mower, and G. Vignale, Ambipolar spin diffusion and D'yakonov-Perel' spin relaxation in GaAs quantum wells. Physical Review B 79, 115321 (2009). http://link.aps.org/doi/10.1103/PhysRevB.79.115321
Items in KU ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.
We want to hear from you! Please share your stories about how Open Access to this item benefits YOU.