EXTENSION OF THE KRONIG-PENNEY MODEL FOR GAMMA-X MIXING IN SUPERLATTICES

An extension of the Kronig-Penney model to treat mixings of different valleys in superlattices is presented. The value of the mixing paramet er alpha used in the model is deduced by comparison with more sophisti cated theory and various experiments for the GaAs/A]As material system . It is shown that with the use of a single value for the mixing param eter, this simple and efficient model can reasonably reproduce the imp ortant aspects of valley mixing effects in GaAs/AlAs superlattices ove r a wide range of layer thicknesses.