Grynyshyn Y. Theory of the absorption band of electromagnetic field by quantum cascade detector in the model of expanded active region

Thesis deals with the investigation of electronic transport through the resonant tunneling structures, being the basic elements of quantum cascade detectors in the models of closed and open cascade. In the thesis, for the first time, the consistent quantum mechanical theory of electron-phonon interaction is developed, its effect on the renormalized spectral characteristics of electron in nano-structure is studied and analyzed. It is shown that due to the weak electron-phonon binding, at the varying temperature of the system, the phonons weakly change the energies of electron states and, thus, their contribution into formation of absorption band of electromagnetic field, arising at the quantum transition, is small.