Hole antiresonances above quantum wells

We use the 6x6 Luttinger-Kohn Hamiltonian to study the effects of the spin-orbit split-off band on the properties of holes tunneling across quantum wells. The transmission coefficients of heavy and light holes decrease sharply (antiresonances) at energies coinciding with the formation of bound states in two effective potential wells for the light and SO bands. The origin of these effective potential wells is due to the difference between the threshold energies for free propagation in the quantum well and cladding layers for holes in the light and SO bands. The dwell times of holes increase sharply at the antiresonance energies and are found to reach a maximum at some values of the transverse wave vector for holes incident with a fixed energy. The probability of heavy- to light-hole conversion (and vice versa) is found to increase at the antiresonance energies. These results are compared with the predictions of a one-band effective-mass description of hole transport to stress the importance of the coupling between the hole subbands on the tunneling properties of holes across quantum wells. (C) 1999 American Institute of Physics. [S0021-8979(99)00502-2].