TIME-RESOLVED PHOTOLUMINESCENCE IN THE FRACTIONAL QUANTUM HALL REGIME

Photoluminescence (PL) spectra from excitons in the 2D electron layer in GaAs shows anomalous behavior that reflects the intrinsic propertie s of the strongly interacting 2D electron system. In the regime of the fractional quantum Hall effect an additional spectral peak is observe d for Landau filling factor nu < 1/2. At nu = 1/3 a dramatic transfer of intensity between the peaks is observed which is coincident with a sharp increase in the PL decay times. This effect is influenced by cha nges in electron-hole overlap as a result of changes in the polarizabi lity of the Laughlin fluid/electron gas. In the extreme quantum limit nu < 1/4, the PL decay time for the higher-energy peak decreases while the lower-energy peak decay time increases.