Transport of Indirect Excitons in High Magnetic Fields
  We present spatially- and spectrally-resolved photoluminescence measurements of indirect excitons in high magnetic fields. Long indirect exciton lifetimes give the opportunity to measure magnetoexciton transport by optical imaging. Indirect excitons formed from electrons and holes at zeroth Landau levels (0e - 0h indirect magnetoexcitons) travel over large distances and form a ring emission pattern around the excitation spot. In contrast, the spatial profiles of 1e - 1h and 2e - 2h indirect magnetoexciton emission closely follow the laser excitation profile. The 0e - 0h indirect magnetoexciton transport distance reduces with increasing magnetic field. These effects are explained in terms of magnetoexciton energy relaxation and effective mass enhancement. 
Y. Y. Kuznetsova, C. J. Dorow, E. V. Calman, L. V. Butov, J. Wilkes,   K. L. Campman, and A. C. Gossard
cond-mat.mes-hall