Spin splitting of conduction subbands in Al0.3Ga0.7As/GaAs/AlxGa As/Al0.3Ga0.7As step quantum wellsY. F. Hao, Y. H. Chen, Y. Liu and Z. G. WangEPL, 85 3 (2009) 37003DOI: https://doi.org/10.1209/0295-5075/85/37003