Abstract:

The transport properties of a spin-split 2D electron gas system in an In0.53Ga0.47As/InP quantum well structure show interesting spin-related dynamics, even though only one electronic subband is occupied. An analytical method is developed to extract the quantum mobilities for the two spin subbands. Ionized impurity scattering and alloy disorder scattering are found to be the dominant mechanisms in this system. A larger quantum mobility is found for the higher-energy spin subband and the difference between the quantum mobilities for the two spin subbands can be tuned with the gate voltage. There exists a strong spin-orbit interaction in the 2D electron gas in the gated high-mobility In0.53Ga0.47As/InP quantum well. It is establish that the spin-orbit interaction is dominated by Rashba mechanism. Rashba spin-orbit coupling parameters determined from both the weak anti-localization and the beating pattern in Shubnikov-de Haas oscillations are in reasonable agreement with those derived from a simple kƒ8¥6p model. The zero-field spin splitting deduced from experiment shows non-monotonic behavior with a maximum as the electron density is varied by the applied gate voltage, which is satisfactorily explained within the Rashba model.
 
 
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