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Title: Spin relaxation in n-type GaAs quantum wells from a fully microscopic approach

Abstract

We perform a full microscopic investigation on the spin relaxation in n-type (001) GaAs quantum wells with an Al{sub 0.4}Ga{sub 0.6}As barrier due to the D'yakonov-Perel' mechanism from nearly 20 K to room temperature by constructing and numerically solving the kinetic spin Bloch equations. We consider all the relevant scattering such as the electron-acoustic-phonon, the electron-longitudinal-optical-phonon, the electron-nonmagnetic-impurity, and the electron-electron Coulomb scattering to the spin relaxation. The spin relaxation times calculated from our theory with a fitting spin splitting parameter are in good agreement with the experimental data by Ohno et al. [Physica E (Amsterdam) 6, 817 (2000)] over the whole temperature regime (from 20 to 300 K). The value of the fitted spin splitting parameter agrees with many experiments and theoretical calculations. We further show the temperature dependence of the spin relaxation time under various conditions such as electron density, impurity density, and well width. We predict a peak solely due to the Coulomb scattering in the spin relaxation time at low temperature (<50 K) in samples with low electron density (e.g., density less than 1x10{sup 11} cm{sup -2}) but high mobility. This peak disappears in samples with high electron density (e.g., 2x10{sup 11} cm{sup -2}) and/or lowmore » mobility. The hot-electron spin kinetics at low temperature is also addressed with many features quite different from the high-temperature case predicted.« less

Authors:
;  [1];  [2];  [3]
  1. Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)
  2. (China)
  3. Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)
Publication Date:
OSTI Identifier:
20976667
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 75; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevB.75.045305; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM COMPOUNDS; BLOCH EQUATIONS; COULOMB SCATTERING; DENSITY; ELECTRON DENSITY; ELECTRON MOBILITY; ELECTRON-PHONON COUPLING; ELECTRONS; EXCHANGE INTERACTIONS; GALLIUM ARSENIDES; QUANTUM WELLS; RELAXATION; RELAXATION TIME; SEMICONDUCTOR MATERIALS; SPIN; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K

Citation Formats

Zhou, J., Wu, M. W., Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, and Cheng, J. L. Spin relaxation in n-type GaAs quantum wells from a fully microscopic approach. United States: N. p., 2007. Web. doi:10.1103/PHYSREVB.75.045305.
Zhou, J., Wu, M. W., Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, & Cheng, J. L. Spin relaxation in n-type GaAs quantum wells from a fully microscopic approach. United States. doi:10.1103/PHYSREVB.75.045305.
Zhou, J., Wu, M. W., Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, and Cheng, J. L. Mon . "Spin relaxation in n-type GaAs quantum wells from a fully microscopic approach". United States. doi:10.1103/PHYSREVB.75.045305.
@article{osti_20976667,
title = {Spin relaxation in n-type GaAs quantum wells from a fully microscopic approach},
author = {Zhou, J. and Wu, M. W. and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 and Cheng, J. L.},
abstractNote = {We perform a full microscopic investigation on the spin relaxation in n-type (001) GaAs quantum wells with an Al{sub 0.4}Ga{sub 0.6}As barrier due to the D'yakonov-Perel' mechanism from nearly 20 K to room temperature by constructing and numerically solving the kinetic spin Bloch equations. We consider all the relevant scattering such as the electron-acoustic-phonon, the electron-longitudinal-optical-phonon, the electron-nonmagnetic-impurity, and the electron-electron Coulomb scattering to the spin relaxation. The spin relaxation times calculated from our theory with a fitting spin splitting parameter are in good agreement with the experimental data by Ohno et al. [Physica E (Amsterdam) 6, 817 (2000)] over the whole temperature regime (from 20 to 300 K). The value of the fitted spin splitting parameter agrees with many experiments and theoretical calculations. We further show the temperature dependence of the spin relaxation time under various conditions such as electron density, impurity density, and well width. We predict a peak solely due to the Coulomb scattering in the spin relaxation time at low temperature (<50 K) in samples with low electron density (e.g., density less than 1x10{sup 11} cm{sup -2}) but high mobility. This peak disappears in samples with high electron density (e.g., 2x10{sup 11} cm{sup -2}) and/or low mobility. The hot-electron spin kinetics at low temperature is also addressed with many features quite different from the high-temperature case predicted.},
doi = {10.1103/PHYSREVB.75.045305},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 4,
volume = 75,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}