Resonant tunneling of holes in double-barrier heterostructures in the envelope-function approximation

A transfer-matrix calculation of the resonant tunneling of holes in double-barrier heterostructures is presented, based on a four-band description of hole subbands. The mixing of heavy- and light-hole channels at nonvanishing in-plane k vectors produces a variety of line shapes of the transmission coefficient through different resonances, some of which with pronounced asymmetry. Most of these asymmetric line shapes are suppressed by the integration over initial states contributing to the tunneling current between two p-type electrodes. The mixing effects increase with the thickness of the barriers. A discussion of the relevance of these calculations for the interpretation of measurements and for the design of new experiments is presented.