The possibility of radiative excitation of internal degrees of freedom of a polaron in a crystal

A method is developed for transforming the Froelich Hamiltonian describing the interaction of an electron with the longitudinal acoustic branch of a crystal into the Hamiltonian of two interacting particles, the electron and the phonon coat. This concept was first proposed by Feynman and forms the basis for the Bogolyubov linear model of a polaron. The approach presented complements the linear model. It is suggested that the center of masses of an electron and coat be considered a polaron coordinate and the degree of freedom of their relative motion be considered an internal degree of freedom of polaron. The internal degree of freedom is shown to be optically active and may be excited by radiation in the visible range. Estimates of the mechanical and optical parameters of the model are presented. 18 refs