PARAMETER CONSISTENCY IN MULTIENERGETIC K-CENTER-DOT-P MODELS

Standard derivations of multiband k . p models rely on Lowdin perturbation theory. Close examination of this method, however, reveals that it is unsuitable for treating systems with multiple zeroth-order energies. As a result, various perturbation sums in multienergetic k . p models are not well defined, and a consistent set of k . p parameters cannot be guaranteed. We inspect this difficulty and present an alternative derivation of the k . p theory based on the method of infinitesimal basis transformations. This approach clearly demonstrates that a consistent k . p matrix can be generated from an arbitrary number of zeroth-order wave functions regardless of their energies. In addition, we obtain a corrected expression for off-diagonal perturbation sums. The expression is applied to give the corrected form for the asymmetric B parameter in the s-p-coupled zinc-blende k . p Hamiltonian.