CARRIER SPIN DYNAMICS IN CDTE CD1-XMNXTE QUANTUM-WELLS/

We investigated the carrier spin dynamics in diluted magnetic semicond uctor quantum wells, CdTe/Cd1-xMnxTe (x approximate to 0.35), using fe mtosecond time-resolved circular dichroic spectroscopy. When the heavy -hole exciton was resonantly excited by the circularly polarized laser pulse, the positive and negative circular dichroism appeared at the h eavy-hole-and the light-hole-exciton energy, respectively. They decay with different time constants, from which we succeeded in determining the spin dynamics of electrons separately from that of holes. Furtherm ore, we found that the electron-spin-relaxation time decreases dramati cally with decreasing the well width, while the heavy-hole-spin relaxa tion is relatively insensitive to the variation of the well width. Thi s strongly suggests that the electron-spin-relaxation process is gover ned by the s-d exchange interaction in the magnetic barrier layer, whi le the heavy-hole-spin relaxation by p-d exchange interaction is regul ated by the degree of the mixing between the heavy-and light-hole subb ands.