An alternative way of calculating the superlattice Green function for discrete media

We present an alternative and efficient way for calculating the superlattice Green function for discrete systems. The idea is to consider the superlattices as a crystal with the unit cell having the size of the superlattice period in the growth direction. The calculation method takes into account the matrix structure of the system Hamiltonian and a block tridiagonal matrix inversion algorithm. To illustrate the method we study the electronic band structure of a semiconductor superlattice described by means of an empirical sp3s* tight-binding Hamiltonian, including nearest-neighbor interactions and spin–orbit coupling.