L-valley-derived states in (001) GaSb/AlSb quantum wells and superlattices

The energy levels of quantized states derived from the L valleys in GaSb/AlSb (001) quantum wells and superlattices are examined using the one-band Wannier orbital model. It is found that the intervalley mixing between the (1/2,1/2,1/2) and the (1/2,1/2,-1/2) L valleys plays a critical role in determining the electronic structure. Furthermore, an effective-mass approximation scheme is developed to analyze intervalley mixing in quantum-well problems. This scheme provides a good qualitative understanding of intervalley mixing in quantum-well systems, and its results compare favorably with those obtained by the Wannier orbital model.