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Difference equations in condensed matter physics and their application to exciton systems in thin molecular films

Domenii publicaţii > Fizica + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: V. Sajfert, J. Setrajcic, Dusan Popov, B. Tosic

Editorial: Physica A, 353, p.217-234, 2005.

Rezumat:

The main goal of this work is the development of the correct methodology of calculation of the Green’s function of broken symmetry structures. The two methods were analysed and it was concluded that the direct method with the use of the translational opeartors is not convenient for the analysis of the exciton properties in thin molecular films. The second proposed method, consisting in translation of the difference equation with nthe spatially variable parameter into the system of difference equations with constant parameters, was applied to the thin molecular film and the solution of this system, being Green’s function depending on two spatial indices, separately, was found exactly. With help of this Green’s function the spatial dependence of exciton concentration is discussed and it was concluded that on the basis of the found spatial dependence of exciton concentration can be determined such boundary conditions of thin molecular filmwhich lead to high exciton concentrations and consequently to the possibility of construction of high power lasers.

Cuvinte cheie: difference equations, variable coefficients, operator solving, excitons, boundary conditions