Spin dephasing in n‐type GaAs quantum wells in the presence of high magnetic fields in Voigt configuration

Abstract

AbstractWe perform a many‐body study of the spin dephasing due to the D'yakonov–Perel' (DP) effect in n‐type GaAs (100) quantum wells under high magnetic fields in the Voigt configuration by constructing and numerically solving the kinetic Bloch equations. We include all spin‐conserving scattering, such as electron–phonon, electron–non‐magnetic impurity as well as electron–electron Coulomb scattering, in our theory and investigate how the spin dephasing time (SDT) is affected by the initial spin polarization, impurity, and magnetic field. The dephasing obtained from our theory contains not only that due to the effective spin‐flipping scattering first proposed by DP [M. I. D'yakonov and V. I. Perel', Zh. Eksp. Teor. Fiz. 60, 1954 (1971); Sov. Phys. – JETP 38, 1053 (1971)], but also the recently proposed many‐body dephasing due to the inhomogeneous broadening provided by the DP term [M. W. Wu, J. Supercond.: incorp. Novel Mechanism 14, 245 (2001); M. W. Wu and C. Z. Ning, Eur. Phys. J. B 18, 373 (2000)]. We are able to investigate the spin dephasing with extra‐large spin polarization (up to 100%), which has not been discussed either theoretically or experimentally. A huge anomalous resonance of the SDT for large spin polarizations is predicted under the high magnetic field we used. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)