Spin-injection dynamics in a magnetic double quantum well studied by pump-probe absorption spectroscopy

摘要

We study spin-injection dynamics in a magnetic double quantum well by pump-probe absorption spectroscopy. Time dependences of the absorption saturation intensity show a tunneling of spin-polarized carriers from a diluted magnetic well (MW) of Cd_(0.92)Mn_(0.08)Te into a nonmagnetic well (NMW) of CdTe, where the individual tunneling of the electron and heavy hole is elucidated with time constants of 150 ps and 1 ns. The circular polarization degree of the absorption saturation in NMW increases from 0 to 70 ps, which is caused by the injection of electron spin polarized in MW with a time constant of 54 ps.