Current-induced spin polarization in InGaAs and GaAs epilayers with varying doping densities

Abstract

The current-induced spin polarization and momentum-dependent spin-orbit field were measured in In${}_x$Ga${}_{1-x}$As epilayers with varying indium concentrations and silicon doping densities. Samples with higher indium concentrations and carrier concentrations and lower mobilities were found to have larger electrical spin generation efficiencies. Furthermore, current-induced spin polarization was detected in GaAs epilayers despite the absence of measurable spin-orbit fields, indicating that the extrinsic contributions to the spin polarization mechanism must be considered. Theoretical calculations based on a model that includes extrinsic contributions to the spin dephasing and the spin Hall effect, in addition to the intrinsic Rashba and Dresselhaus spin-orbit coupling, are found to qualitatively agree with the experimental results.

16 pages, 8 figures

References in corpus (9)

• Current induced electron spin polarization in strained semiconductors
• Measurement of Rashba and Dresselhaus spin-orbit magnetic fields
• Theory of Spin Hall conductivity in n-doped GaAs
• Current-Induced Polarization and the Spin Hall Effect at Room Temperature
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• Mapping spin-orbit splitting in strained InGaAs epilayers