Browsing by Author "Catanoi, A."

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    Electron collision rate and multiquantum transitions in solids [Articol]
    (2008) Klyukanov, A.; Catanoi, A.; Petrushca, A.; Awawdeh, A.
    Multiquantum integral kinetic equation for the longitudinal complex dielectric function is derived. Heisenberg equation of motion and fluctuation-dissipation theorem has been used to calculate multiplasmon transmission electron energy loss spectra. Strong interaction between high-energy electrons penetrating the solid state and plasma of valence electrons is taken into account. It is shown that average number of high-frequency plasmons generated in every collision process is more than one for typical values of metal parameters. It is obtained that excitation of a good few of plasmons is simultaneous event. Calculated multiplasmon structure of electron energy loss spectra coincides with experimental one.
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    Multiplasmon radiation line replicas of bound excitons in single ZnSe crystals [Articol]
    (2006) Klyukanov, Alexandr; Sushkevici, Konstantin; Chyukichev, M.; Awawdeh, Adnan; Gurau, Virginia; Catanoi, A.
    The cathode-luminescence of ZnSe single crystals, grown from vapour phase and heat treated in Bi melts [ZnSe(Bi)] at 1200 K for 120h, and also in Bi melts doped by Al [ZnSe(Bi, Al)] were investigated at 4.2 K. The LO-phonon replicas of free excitons emission line dominate in cathode-luminescence spectra of the samples heat treated in Bi followed by water quenching. The lines of bound excitons series, nLOI ds −, 1 , were observed in the emission of all samples, including the original ones. It was found that plasmon replicas are not proper only for nLOI s −1 lines, but, also, for nLOI d −1 lines. The weak exciton-plasmon coupling is manifested in one plasmon Stokes side band shoulders of nLOI d −1 lines. It is developed the theory of bound excitons multi-quantum optical transitions with participation of mixed plasmon-phonon oscillation modes. This theory allows for the calculation of the emission spectra form–function, without using any model. The theoretical spectra are in agreement with the experimental data.