Spin splitting of conduction subbands in Al0.3Ga0.7As/GaAs/AlxGa1-x As/Al0.3Ga0.7As step quantum wellsY. F. Hao, Y. H. Chen, Y. Liu and Z. G. Wang
Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences - P.O. Box 912, Beijing 100083, PRC
received 1 September 2008; accepted in final form 12 January 2009; published February 2009
published online 13 February 2009
By means of the transfer matrix technique, interface-induced Rashba spin splitting of conduction subbands in Al0.3Ga0.7As/GaAs/AlxGa1- xAs/Al0.3Ga0.7As step quantum wells which contain internal structure inversion asymmetry introduced by the insertion of AlxGa1- xAs step potential is investigated theoretically in the absence of electric field and magnetic field. The dependence of spin splitting on the well width, step width and Al concentration is investigated in detail. We find that the sign of the first excited subband spin splitting changes with well width and step width, and is opposite to that of the ground subband under certain conditions. The sign and strength of the spin splitting are shown to be sensitive to the components of the envelope function at three interfaces.
71.70.Ej - Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect.
71.23.An - Theories and models; localized states.
© EPLA 2009