Atomistic spin-orbit coupling and k center dot p parameters in III-V semiconductors

The most accurate description of spin splittings in semiconductor nanostructures has been obtained from a 14-band k center dot p model, but the historical way in which it has developed from the 8-band Kane model has endorsed somewhat arbitrary values of the momentum and spin-orbit matrix elements. We have systematically determined the 14-band k center dot p parameters for III-V semiconductors from a 40-band tight-binding model. Significant changes with respect to previously accepted values were found even for GaAs. For all materials investigated, the resulting Dresselhaus spin-orbit coupling parameter is in good agreement with experimental values. The atomistic background of the present parametrization allows new insight into the spin-orbit coupling Delta(-) between bonding and antibonding orbitals and its dependence on ionicity.