Detection of large magneto-anisotropy of electron spin dephasing in a high-mobility two-dimensional electron system in a $[001]$ GaAs/AlGaAs quantum well

Abstract

In time-resolved Faraday rotation experiments we have detected an inplane anisotropy of the electron spin-dephasing time (SDT) in an $n$--modulation-doped GaAs/Al${}_{0.3}$Ga${}_{0.7}$As single quantum well. The SDT was measured with magnetic fields of $B\le 1$ T, applied in the $[110]$ and $[1\bar{1}0]$ inplane crystal directions of the GaAs quantum well. For fields along $[1\bar{1}0]$, we have found an up to a factor of about 2 larger SDT than in the perpendicular direction. Fully microscopic calculations, by numerically solving the kinetic spin Bloch equations considering the D'yakonov-Perel' and the Bir-Aronov-Pikus mechanisms, reproduce the experimental findings quantitatively. This quantitative analysis of the data allowed us to determine the relative strengths of Rashba and Dresselhaus terms in our sample. Moreover, we could estimate the SDT for spins aligned in the $[110]$ {\em inplane} direction to be on the order of several nanoseconds, which is up to two orders of magnitude larger than that in the perpendicular {\em inplane} direction.

4 pages, 4 figures, to be published in PRB

References in corpus (4)

• High temperature spin dephasing in n-typed GaAs quantum wells
• Hot-electron effect in spin dephasing in $n$-type GaAs quantum wells
• Anisotropic spin transport in GaAs quantum wells in the presence of competing Dresselhaus and Rashba spin-orbit-coupling strengths
• Spin relaxation under identical Dresselhaus and Rashba coupling strengths in GaAs quantum wells

Cited by in corpus (2)

• Spin relaxation due to the Bir-Aronov-Pikus mechanism in intrinsic and $p$-type GaAs quantum wells from a fully microscopic approach
• Kinetics of spin coherence of electrons in $n$-type InAs quantum wells under intense terahertz laser fields