Tunneling of spin polarized excitons in CdTe based asymmetric double quantum well structure

We have studied by means of cw magnetospectroscopy the tunneling of photoex cited carriers from a Cd1-xMnxTe spin-aligning QW to a CdTe QW through a Cd 1-yMgyTe barrier. PLE results suggest that we deal with the tunneling of ex citons as whole entities and that the effectiveness of the transfer is high est when exciton energy detuning equals two LO phonon energies. We observed that, during tunneling, photocarriers keep a substantial amount of their s pin polarization, amounting to about 10%. The results prove that the inject ing spin polarized excitons from spin-aligning QW to another QW via tunneli ng effect is feasible, and may lead to considerable spin populations. (C) 2 001 Elsevier Science Ltd. All rights reserved.