We examine the influence of band mixing on hole-tunneling times in GaAs/AlAs double-barrier heterostructures using the eight-band effective bond-orbital model. We find that mixing of heavy-hole and light-hole states in the valence subbands can substantially reduce hole-tunneling times from the values predicted by the Kronig-Penney model, which does not account for band mixing. These results are in agreement with the experimental measurements of Jackson et al. [Appl. Phys. Lett. 54, 552 (1989)], indicating that hole-tunneling times are much shorter than predicted by the Kronig-Penney model, and comparable in fact to electron-tunneling times. We also compare our calculation with an earlier phenomenological model for incorporating band-mixing effects in the calculation of hole-tunneling times.

• Received 14 October 1991

DOI:https://doi.org/10.1103/PhysRevB.45.3576