Peierls transition in organic crystals of TTT2I3 for different values of carrier concentration

Abstract

Peierls transition in quasi-one-dimensional organic crystals of tetrathiotetracene-iodide, TTT2I3, is investigated in 3D approximation. For a more complete description of the crystal model, two the most important hole-phonon interactions are considered. The first is similar to that of deformation potential and the second one is of polaron type. The scattering on defects is also considered. The renormalized phonon spectrum is calculated in the random phase approximation for different temperatures applying the method of retarded Green functions. The transition behavior is investigated for different values of carrier concentration that is determined by the dimensionless Fermi momentum, kF. In all cases the critical temperature of the transition is determined.