No abstract

No abstract

Photoluminescence spectra from 6-doped n-type A1~Ga&~As/In&Ga"As/GaAs quantum wells have been investigated in magnetic fields H(14 T and T=1.8-18 K. The Fermi level of the quasitwo-dimensional electron gas EF was slightly below the second subband. Interband Landau-level (LL) transitions between the j, th electron LL (j, =1,2) and the first hole LL, j, -l j"were analyzed. Their intensity was found to increase anomalously when the transition energy intersected that of the magnetoexciton state involving the electron from the second subband, 0,-0q. The intensity of the 0,-0& line oscillated with magnetic field and its maxima coincided with the intersection between the 0,-0j, energy and either the j, -0& or j, -1h transitions or both of them, depending on the energy separation between EI; and the second subband. Taking into account that the j, -1& and O, -OI, transitions involve no common particle, the anomalous behavior is explained by the interaction between two magnetoexciton states, 0,-0& and j, -l j, .