Peculiarities of ultrasonic propagation in quasi-one-dimensional Peierls dielectrics
Abstract
The theory is constructed for the propagation of longitudinal ultrasound in a quasi-one-dimensional Peierls dielectric (of the type TaS3) containing a charge density wave (CDW). It is shown that if kinks are excited in a CDW by an electric field, they would induce kink-like nonlinear excitations in the acoustic subsystem as a result of deformation interaction. The bound states of CDW and sound propagate at velocities differing from the velocity of sound. These nonlinear excitations can be observed in the scattering of small-amplitude ultrasound. The scattering of linear ultrasound by kinks produces a giant amplitude enhancement in the transmitted wave and the reflected wave also has a similarly large amplitude.