Reduced Hamiltonian for Electronic States of Dilute Nitride   Semiconductors
  We present a novel model to describe conduction band of GaN_xAs_{1-x} (GaNAs). As well known, GaNAs shows exotic behavior such as large band gap bowing. Although there are various models to describe the conduction band of GaNAs, origin of the band gap bowing is still under debate. On the basis of perturbation theory, we show that the behavior of conduction band is mainly arising from intervalley mixing between Gamma and L or X. By using renormalization technique and group theoretical treatment, we derive a reduced Hamiltonian which describes well the band gap shrinkage of GaNAs. 
Masato Morifuji and Fumitaro Ishikawa
cond-mat.mtrl-sci