Cyclotron-resonant exciton transfer between the nearly free and strongly   localized radiative states of a two-dimensional hole gas in a high magnetic   field
  Avoided crossing of the emission lines of a nearly free positive trion and a cyclotron replica of an exciton bound to an interface acceptor has been observed in the magneto-photoluminescence spectra of p-doped GaAs quantum wells. Identification of the localized state depended on the precise mapping of the anti-crossing pattern. The underlying coupling is caused by an exciton transfer combined with a resonant cyclotron excitation of an additional hole. The emission spectrum of the resulting magnetically tunable coherent state probes weak localization in the quantum well. 
L. Bryja, J. Jadczak, A. Wojs, G. Bartsch, D. R. Yakovlev, M. Bayer,   P. Plochocka, M. Potemski, D. Reuter, A. D. Wieck
cond-mat.str-el