Experimental analysis of the spin-orbit coupling dependence on the drift velocity of a spin packet

Abstract

Spin transport was studied in a two-dimensional electron gas hosted in a wide GaAs quantum well occupying two subbands. Using space and time Kerr rotation microscopy to image drifting spin packets under an in-plane accelerating electric field, optical injection and detection of spin polarization were achieved in a pump-probe configuration. The experimental data exhibited high spin mobility and long spin lifetimes allowing to obtain the spin-orbit fields as a function of the spin velocities. Surprisingly, above moderate electric fields of 0.4V/cm with velocities higher than 2$\mu$m/ns, we observed a dependence of both bulk and structure-related spin-orbit interactions on the velocity magnitude. A remarkable feature is the increase of the cubic Dresselhaus term to approximately half of the linear coupling when the velocity is raised to 10$\mu$m/ns. In contrast, the Rashba coupling for both subbands decreases to about half of its value in the same range. These results yield new information for the application of drift models in spin-orbit fields and about limitations for the operation of spin transistors.

arXiv comment5 pages, 3 figures

References in corpus (15)

• Spintronics: Fundamentals and applications
• Non-ballistic spin field-effect transistor
• An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System
• Emergence of the persistent spin helix in semiconductor quantum wells
• Spin Hall effect transistor
• Direct mapping of the formation of a persistent spin helix: Supplementary information
• Persistent Spin Textures in Semiconductor Nanostructures
• Datta-Das transistor with enhanced spin control
• Current-controlled Spin Precession of Quasi-Stationary Electrons in a Cubic Spin-Orbit Field
• Datta-Das type spin-field effect transistor in non-ballistic regime
• Spin drift and diffusion in one- and two-subband helical systems
• Macroscopic transverse drift of long current-induced spin coherence in two-dimensional electron gases
• Gate control of the spin mobility through the modification of the spin-orbit interaction in two-dimensional systems
• Resonant optical control of the electrically-induced spin polarization by periodic excitation
• g-Factor Modification in a Bulk InGaAs Epilayer by an In-plane Electric Field

Cited by in corpus (1)

• Electrical control of spin relaxation anisotropy during drift transport in a two-dimensional electron gas