Spin-polarized excitons in long-range ordered Ga/sub 0.5/In/sub 0.5/P

Circularly polarized excitation light produces spin-polarized excitons in long-range ordered Ga/sub 0.5/In/sub 0.5/P, because of a splitting at the valence-band maximum. We observed the spin relaxation process in ordered Ga/sub 0.5/In/sub 0.5/P under resonant excitation of heavy-hole excitons. The circularly polarized exciton luminescence shows a maximum anisotropy of about 35%. The decay profile of the depolarized luminescence is described by two components; the rapid decay by exciton-relaxation processes and the slower exciton recombination. An excitonic spin-relaxation process occurrs during the initial rapid decay.