TY - JOUR

T1 - Experimental analysis of the spin-orbit coupling dependence on the drift velocity of a spin packet

AU - Kawahala, N. M.

AU - Moraes, F. C.D.

AU - Gusev, G. M.

AU - Bakarov, A. K.

AU - Hernandez, F. G.G.

PY - 2020/6/1

Y1 - 2020/6/1

N2 - 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 us to obtain the spin-orbit fields as a function of the spin velocities. Surprisingly, above moderate electric fields of 0.4 V/cm with velocities higher than 2 μm/ns, we observed a dependence of both bulk and structure-related spin-orbit interactions on the velocity magnitude. A remarkable feature is the increase in the cubic Dresselhaus term to approximately half of the linear coupling when the velocity is raised to 10 μm/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 on the application of drift models in spin-orbit fields and about limitations for the operation of spin transistors.

AB - 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 us to obtain the spin-orbit fields as a function of the spin velocities. Surprisingly, above moderate electric fields of 0.4 V/cm with velocities higher than 2 μm/ns, we observed a dependence of both bulk and structure-related spin-orbit interactions on the velocity magnitude. A remarkable feature is the increase in the cubic Dresselhaus term to approximately half of the linear coupling when the velocity is raised to 10 μm/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 on the application of drift models in spin-orbit fields and about limitations for the operation of spin transistors.

KW - SPINTRONICS

UR - http://www.scopus.com/inward/record.url?scp=85087544716&partnerID=8YFLogxK

U2 - 10.1063/5.0016108

DO - 10.1063/5.0016108

M3 - Article

AN - SCOPUS:85087544716

VL - 10

JO - AIP Advances

JF - AIP Advances

SN - 2158-3226

IS - 6

M1 - 065232

ER -