Microscopic theory for the Doppler velocimetry of spin propagation in semiconductor quantum wells
arXiv:1208.1081 · doi:10.1103/PhysRevB.86.205307
Abstract
We provide a microscopic theory for the Doppler velocimetry of spin propagation in the presence of spatial inhomogeneity, driving electric field and the spin orbit coupling in semiconductor quantum wells in a wide range of temperature regime based on the kinetic spin Bloch equation. It is analytically shown that under an applied electric field, the spin density wave gains a time-dependent phase shift . Without the spin-orbit coupling, the phase shift increases linearly with time and is equivalent to a normal Doppler shift in optical measurements. Due to the joint effect of spin-orbit coupling and the applied electric field, the phase shift behaviors differently at the early and the later stages. At the early stage, the phase shifts are the same with or without the spin-orbit coupling. While at the later stage, the phase shift deviates from the normal Doppler one when the spin-orbit coupling is present. The crossover time from the early normal Doppler behavior to the anomalous one at the later stage is inversely proportional to the spin diffusion coefficient, wave vector of the spin density wave and the spin-orbit coupling strength. In the high temperature regime, the crossover time becomes large as a result of the decreased spin diffusion coefficient. The analytic results capture all the quantitative features of the experimental results, while the full numerical calculations agree quantitatively well with the experimental data obtained from the Doppler velocimetry of spin propagation [Yang {\it et al.}, Nat. Phys. {\bf 8}, 153 (2012)]. We further predict that the coherent spin precession, originally thought to be broken down at high temperature, is robust up to the room temperature for narrow quantum wells. We point out that one has to carry out the experiments longer to see the effect of the coherent spin precession at higher temperature due to the larger crossover time.
arXiv comment6 pages, 1 figure, PRB in press
References in corpus (35)
- Spintronics: Fundamentals and applications
- Semiconductor Spintronics
- Electronic measurement and control of spin transport in Silicon
- Spin dynamics in semiconductors
- Spin current and polarization in impure 2D electron systems with spin-orbit coupling
- Spin Hall effect transistor
- Theory of Spin-Charge Coupled Transport in a Two-Dimensional Electron Gas with Rashba Spin-Orbit Interactions
- Observation of spin Coulomb drag in a two-dimensional electron gas
- Semiclassical theory of spin transport in spin-orbit coupled systems
- Imaging spin flows in semiconductors subject to electric, magnetic, and strain fields
- Non-diffusive spin dynamics in a two-dimensional electron gas
- Hot-electron effect in spin dephasing in -type GaAs quantum wells
- Spin relaxation in -type GaAs quantum wells from a full microscopic approach
- Spin relaxation in a generic two-dimensional spin-orbit coupled system
- Diffusion equation and spin drag in spin-polarized transport
- Spin diffusion in doped semiconductors: the role of Coulomb interactions
- 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
- Doppler velocimetry of spin propagation in a two-dimensional electron gas
- Theory of electric-field-induced spin accumulation and spin current in the two-dimensional Rashba model
- Longitudinal spin decoherence in spin diffusion in semiconductors
- Datta-Das type spin-field effect transistor in non-ballistic regime
- On boundary conditions for spin diffusion equations with Rashba spin-orbit interaction
- Effects of strain, electric, and magnetic fields on lateral electron spin transport in semiconductor epilayers
- Spin lifetimes and strain-controlled spin precession of drifting electrons in zinc blende type semiconductors
- Transit-Time Spin Field-Effect-Transistor
- Relaxation mechanisms of the persistent spin helix
- Spin Coulomb drag beyond the random phase approximation
- Measurement of electron-hole friction in an n-doped GaAs/AlGaAs quantum well using optical transient grating spectroscopy
- Spin diffusion/transport in -type GaAs quantum wells
- Spin relaxation in -type GaAs quantum wells with transient spin grating
- Diffusion and transport of spin pulses in an -type semiconductor quantum well
- Spin-Hall effect and spin-coherent excitations in a strongly confined two-dimensional hole gas
- Coupled spin-charge drift-diffusion approach for a two-dimensional electron gas with Rashba spin-orbit coupling
- Voltage controlled spin precession in InAs quantum wells