LATTICE SUMS APPROXIMATION IN CRYSTAL DYNAMICS

Александр КЛЮКАНОВ, Александр КОЧЕМАСОВ, Денис НИКА Молдавский государственный университет

Abstract

A model describing an electron-phonon system of a crystal as a system of new quasiparticles, that takes into account both electron and phonon properties of the system, is proposed in this article. The corresponding Hamiltonian of quasiparticles is deduces and on its basis the dynamical matrix elements for a monoatomic crystal are obtained. It is demonstrated that unlike the classical theory the dependence of the dynamical matrix on the lattice vectors is integral. Keywords: lattice sums, crystal dynamics, electrons, phonons, perturbation theory, Heisenberg equations of motion, dynamical matrix.