ENHANCEMENT OF SPIN-DEPENDENT HOLE DELOCALIZATION IN DEGENERATE ASYMMETRIC DOUBLE-QUANTUM WELLS

Exact, self-consistently calculated eigenfunctions and eigenvalues of the valence band in degenerate asymmetric double quantum wells are obt ained from the full 4x4 Luttinger Hamiltonian for different hole densi ties. We found the solutions to be extremely sensitive to the charge d ensity. The charge induces an extra asymmetry in the confining potenti al and leads to a smaller separation of the hole levels in the adjacen t wells. This strongly enhances the different leakage of wave function s with opposite magnetic moment, called spin-dependent hole delocaliza tion (SDHD). Furthermore, it is shown that the SDHD of the heavy-holt: states can be enhanced by increasing the confinement of the Light-hol e states through adjustment of the height of the confining barriers. T he theoretical results are shown to be in excellent agreement with tra nsport and optical experiments, which are proven to be largely determi ned by space-charge effects.