Peierls transition in quasi-one-dimensional crystals of TTF-TCNQ type in a 2D approximation.

Abstract

Peierls transition in quasi-one-dimensional organic crystals of TTF-TCNQ type is studied in a 2D physical model of the crystal. The two most important electron-phonon interactions are simultaneously considered. The analytic expression for the phonon polarization operator is obtained in the random phase approximation. The polarization operator as a function of temperature is calculated for different values of parameter d, where d is the ratio of the transfer energy in the direction transversal to conductive chains to the transfer energy along the conductive chains. Peierls critical temperature Tp is determined for different values of d.