Electron spin relaxation in paramagnetic Ga(Mn)As quantum wells

Abstract

Electron spin relaxation in paramagnetic Ga(Mn)As quantum wells is studied via the fully microscopic kinetic spin Bloch equation approach where all the scatterings, such as the electron-impurity, electron-phonon, electron-electron Coulomb, electron-hole Coulomb, electron-hole exchange (the Bir-Aronov-Pikus mechanism) and the $s$-$d$ exchange scatterings, are explicitly included. The Elliot-Yafet mechanism is also incorporated. From this approach, we study the spin relaxation in both $n$-type and $p$-type Ga(Mn)As quantum wells. For $n$-type Ga(Mn)As quantum wells where most Mn ions take the interstitial positions, we find that the spin relaxation is always dominated by the DP mechanism in metallic region. Interestingly, the Mn concentration dependence of the spin relaxation time is nonmonotonic and exhibits a peak. This behavior is because that the momentum scattering and the inhomogeneous broadening have different density dependences in the non-degenerate and degenerate regimes. For $p$-type Ga(Mn)As quantum wells, we find that Mn concentration dependence of the spin relaxation time is also nonmonotonic and shows a peak. Differently, this behavior is because that the $s$-$d$ exchange scattering (or the Bir-Aronov-Pikus) mechanism dominates the spin relaxation in the high Mn concentration regime at low (or high) temperature, whereas the DP mechanism determines the spin relaxation in the low Mn concentration regime. The Elliot-Yafet mechanism also contributes the spin relaxation at intermediate temperature. The spin relaxation time due to the DP mechanism increases with Mn concentration due to motional narrowing, whereas those due to the spin-flip mechanisms decrease with Mn concentration, which thus leads to the formation of the peak.... (The remaining is omitted due to the space limit)

12 pages, 8 figures, Phys. Rev. B 79, 2009, in press

References in corpus (14)

• Electron spin relaxation in bulk III-V semiconductors from a fully microscopic kinetic spin Bloch equation approach
• High temperature spin dephasing in n-typed GaAs quantum wells
• Optical Properties of III-Mn-V Ferromagnetic Semiconductors
• Effect of initial spin polarization on spin dephasing and electron g factor in a high-mobility two-dimensional electron system
• Hot-electron effect in spin dephasing in $n$-type GaAs quantum wells
• Detection of large magneto-anisotropy of electron spin dephasing in a high-mobility two-dimensional electron system in a $[001]$ GaAs/AlGaAs quantum well
• Multi-subband effect in spin dephasing in semiconductor quantum wells
• Spin relaxation due to the Bir-Aronov-Pikus mechanism in intrinsic and $p$-type GaAs quantum wells from a fully microscopic approach
• Control of spin coherence in $n$-type GaAs quantum wells using strain
• Electron-hole contribution to the apparent s-d exchange interaction in III-V diluted magnetic semiconductors
• Density dependence of spin relaxation in GaAs quantum well at room temperature
• Multi-valley spin relaxation in the presence of high in-plane electric fields in $n$-type GaAs quantum wells
• Kinetics of spin coherence of electrons in $n$-type InAs quantum wells under intense terahertz laser fields
• Self-sustained magnetoelectric oscillations in magnetic resonant tunneling structures