Spin diffusion/transport in $n$-type GaAs quantum wells

Abstract

The spin diffusion/transport in $n$-type (001) GaAs quantum well at high temperatures ($\ge 120$ K) is studied by setting up and numerically solving the kinetic spin Bloch equations together with the Poisson equation self-consistently. All the scattering, especially the electron-electron Coulomb scattering, is explicitly included and solved in the theory. This enables us to study the system far away from the equilibrium, such as the hot-electron effect induced by the external electric field parallel to the quantum well. We find that the spin polarization/coherence oscillates along the transport direction even when there is no external magnetic field. We show that when the scattering is strong enough, electron spins with different momentums oscillate in the same phase which leads to equal transversal spin injection length and ensemble transversal injection length. It is also shown that the intrinsic scattering is already strong enough for such a phenomena. The oscillation period is almost independent on the external electric field which is in agreement with the latest experiment in bulk system at very low temperature [Europhys. Lett. {\bf 75}, 597 (2006)]. The spin relaxation/dephasing along the diffusion/transport can be well understood by the inhomogeneous broadening, which is caused by the momentum-dependent diffusion and the spin-orbit coupling, and the scattering. The scattering, temperature, quantum well width and external magnetic/electric field dependence of the spin diffusion is studied in detail.

12 pages, 6 figures, to be published in J Appl. Phys

References in corpus (15)

• Transport equations for a two-dimensional electron gas with spin-orbit interaction
• High temperature spin dephasing in n-typed GaAs quantum wells
• 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
• Kinetic theory of spin transport in n-typed semiconductor quantum wells
• Spin lifetimes and strain-controlled spin precession of drifting electrons in zinc blende type semiconductors
• Spin relaxation under identical Dresselhaus and Rashba coupling strengths in GaAs quantum wells
• Control of spin coherence in $n$-type GaAs quantum wells using strain
• Spin oscillations in transient diffusion of a spin pulse in n-type semiconductor quantum wells
• Schottky-barrier induced spin dephasing in spin injection
• Diffusion and transport of spin pulses in an $n$-type semiconductor quantum well
• Spin relaxation time, spin dephasing time and ensemble spin dephasing time in $n$-type GaAs quantum wells
• Spin relaxation of "upstream" electrons in quantum wires: Failure of the drift diffusion model
• Spin polarization control by electric field gradients
• Spin injection and accumulation in inhomogeneous semiconductors

Cited by in corpus (7)

• Anisotropic spin transport in GaAs quantum wells in the presence of competing Dresselhaus and Rashba spin-orbit-coupling strengths
• Spin relaxation in $n$-type GaAs quantum wells with transient spin grating
• Electric-field induced spin excitations in two-dimensional spin-orbit coupled systems
• Spin polarization in biased Rashba-Dresselhaus two-dimensional electron systems
• Spin diffusion in Si/SiGe quantum wells: spin relaxation in the absence of D'yakonov-Perel' relaxation mechanism
• Non-Markovian hole spin kinetics in $p$-type 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