Phonon-assisted recombination of intra-subband magnetoexcitons and two-phonon dissociation of magnetorotons in the quantum Hall regime

We predict a double-peak structure of the emission line for inter-Landau-level intra-subband transitions in a strong magnetic field, when electrons occupy an integer number of Landau levels. The higher-energy peak results from the direct optical emission of zero-momentum excitons. The origin of the lower-energy peak is phonon-assisted transitions from the non-zero-momentum exciton states. We also show that the phonon-pulse-induced dissociation of the magnetoroton in the fractional quantum Hall regime occurs as a second-order process in the electron–phonon interaction.