Spin dephasing in n-typed GaAs quantum wells in the presence of high magnetic fields in Voigt configuration

TL;DR

This study models spin dephasing in n-type GaAs quantum wells under high magnetic fields, revealing the effects of various scattering mechanisms and predicting a large resonance in spin dephasing time at high spin polarization.

Contribution

It introduces a comprehensive many-body kinetic theory including all relevant scattering and dephasing mechanisms, and explores spin dephasing at high polarization levels in magnetic fields.

Findings

Spin dephasing time is affected by initial spin polarization, impurities, and magnetic field.

A large anomalous resonance of SDT is predicted at high spin polarization.

The theory accounts for both effective spin-flipping and many-body inhomogeneous broadening mechanisms.

Abstract

We perform a many-body study of the spin dephasing due to the D'yakonov-Perel' effect in n-typed GaAs (100) quantum wells under high magnetic fields in the Voigt configuration by constructing and numerically solving the kinetic Bloch equations. We include all the spin conserving scattering such as electron-phonon, the electron-nonmagnetic impurity as well as the 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 D'yakonov and Perel' [Zh. Eksp. Teor. Fiz. {\bf 60}, 1954 (1971)[Sov. Phys.-JETP {\bf 38}, 1053 (1971)]], but also the recently proposed many-body dephasing due to the inhomogeneous broadening provided by the DP term [Wu, J. Supercond.:Incorp. Novel Mechanism {\bf 14}, 245 (2001); Wu and Ning, Eur. Phys. J. B {\bf 18}, 373 (2000)]. We are able to investigate the spin dephasing with extra large spin polarization (up to 100 %) which has not been discussed both theoretically and experimentally. A huge anomalous resonance of the SDT for large spin polarizations is predicted under the high magnetic field we used.