SPIN EFFECTS IN POLARIZED LUMINESCENCE AT NU=1

Additional features are observed in polarized photoluminescence from e xciton recombination in a spin-polarized GaAs quantum well near fillin g factor v=1. Upon entering the v=1 quantum Hall state, the main spect ral line in sigma(-) polarizaiton broadens by more than a factor of 2, while developing a substantial low-energy tail. In contrast, for sigm a(+) polarization the line remains narrow at v=1. The large polarizati on asymmetry results from different initial electron-spin configuratio ns prior to the recombination. This polarization property, line shape, and v dependence are consistent with a process of-spin ''shakeup'' th at generates spin-wave excitations.