SPIN-DEPENDENT PHOTOLUMINESCENCE AT V=1 FILLING FACTOR

We perform high-resolution, polarized photoluminescence (PL) experimen ts on a high-mobility GaAs/AlGaAs single quantum well near v = I. Upon entering the v = 1 quantum-Hall region the PL shows a remarkable pola rization dependence. For RCP polarization the PL exhibits the usual re duction of the peak intensity, and a cusp in the spectral energy of th e peak. For LCP polarization we observe unanticipated novel behavior: a major change in the PL line shape, and the development of two new pe aks, one above and one below the main emission peak. This large asymme try between RCP and LCP polarizations can be modeled by considering th e initial spin-configuration prior to the recombination of the e-h pai r. Among the models consistent with our observations are a ''shake-up' ' process in which finite-momentum spin waves are generated in the ele ctron system upon recombination in the LCP polarization. (C) 1998 Else vier Science B.V. All rights reserved.