Spin relaxation in $n$-type GaAs quantum wells with transient spin grating

Abstract

By solving the kinetic spin Bloch equations, we study the time evolution of the transient spin grating, whose spin polarization varies periodically in real space, confined in (001) GaAs quantum wells. With this study we can investigate the properties of both the spin transport and the spin relaxation at the same time. The Fourier component of the spin signal decays double exponentially with two decay rates $1/{\tau }_{+}$ and $1/{\tau }_{-}$. In high temperature regime, the average of these two rates varies with the grating wave-vector $q$ quadratically, i.e., $(1/{\tau }_{+}+1/{\tau }_{-})/2=D_s{q}^2+1/{\tilde{\tau }}_s$, with $D_s$ and ${\tilde{\tau }}_s$ representing the spin diffusion coefficient and the average of the out-of-plane and the in-plane spin relaxation times respectively. ${\tau }_{\pm }$ calculated from our theory are in good agreement with the experimental data by Weber {\em et al.} [Phys. Rev. Lett. {\bf 98}, 076604 (2007)]. By comparing $D_s$ with and without the electron-electron Coulomb scattering, we calculate the contribution of Coulomb drag to the spin diffusion coefficient. With the transient spin grating result, we further reveal the relations among different characteristic parameters such as spin diffusion coefficient $D_s$, spin relaxation time ${\tau }_s$, and spin injection length $L_s$. We show that in the presence of the Dresselhaus and/or Rashba spin-orbit coupling, the widely used relation $L_s=\sqrt{D_s{\tau }_s}$ is generally inaccurate and can even be very wrong in some special cases. We present an accurate way to extract the steady-state transport characteristic parameters from the transient spin grating signals.

9 pages, 4 figures, to be published in JAP

References in corpus (20)

• Spintronics: Fundamentals and applications
• Basic obstacle for electrical spin-injection from a ferromagnetic metal into a diffusive semiconductor
• An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System
• Theory of Spin-Charge Coupled Transport in a Two-Dimensional Electron Gas with Rashba Spin-Orbit Interactions
• Spin-polarized transport in inhomogeneous magnetic semiconductors: theory of magnetic/nonmagnetic p-n junctions
• Observation of spin Coulomb drag in a two-dimensional electron gas
• Spin diffusion in doped semiconductors
• Spin injection through the depletion layer: a theory of spin-polarized p-n junctions and solar cells
• High temperature spin dephasing in n-typed GaAs quantum wells
• Non-diffusive spin dynamics in a two-dimensional electron gas
• Hot-electron effect in spin dephasing in $n$-type GaAs quantum wells
• Spin relaxation in $n$-type GaAs quantum wells from a full microscopic approach
• Spin relaxation in a generic two-dimensional spin-orbit coupled system
• Coulomb interaction effects in spin-polarized transport
• Spin Coulomb drag in the two-dimensional electron liquid
• Kinetic theory of spin transport in n-typed semiconductor quantum wells
• Anisotropic spin transport in GaAs quantum wells in the presence of competing Dresselhaus and Rashba spin-orbit-coupling strengths
• Longitudinal spin decoherence in spin diffusion in semiconductors
• Spin diffusion/transport in $n$-type GaAs quantum wells
• Diffusion and transport of spin pulses in an $n$-type semiconductor quantum well

Cited by in corpus (17)

• Emergence of the persistent spin helix in semiconductor quantum wells
• Spin dynamics in semiconductors
• Observation of exciton-exciton interaction mediated valley depolarization in monolayer MoSe${}_2$
• Theory of coupled spin-charge transport due to spin-orbit interaction in inhomogeneous two-dimensional electron liquids
• Spin-Hall effect and spin-Coulomb drag in doped semiconductors
• Relaxation mechanisms of the persistent spin helix
• Electric-field induced spin excitations in two-dimensional spin-orbit coupled systems
• Spontaneous Emergence of Persistent Spin Helix from Homogeneous Spin Polarization
• Radial Spin Helix in Two-Dimensional Electron Systems with Rashba Spin-Orbit Coupling
• Kinetics of Spin Relaxation in Wires and Channels: Boundary Spin Echo and Tachyons
• Ambipolar spin transport in (111) GaAs quantum wells
• Infinite spin diffusion length of any spin polarization along direction perpendicular to effective magnetic field from Dresselhaus and Rashba spin-orbit couplings with identical strengths in (001) GaAs quantum wells
• Evolution of the persistent spin helix in the presence of Hartree-Fock fields
• Collective Spin-Hall Effect for Electron-Hole Gratings
• Microscopic theory for the Doppler velocimetry of spin propagation in semiconductor quantum wells
• Spin relaxation in Rashba rings
• Dynamics of Spin Relaxation in Finite-Size 2D Systems: an Exact Solution