Low-temperature thermal conduction and sound damping in a disordered quasi-one-dimensional crystal with a weakly dispersive branch of the vibrations Available to Purchase

This paper discusses the question of how the weak localization of the low-energy acoustic vibrational mode, whose dispersion law has a large flat section, affects the propagation of sound and heat in a nonideal chainlike crystal. Analytical expressions are obtained for the thermal-conduction and sound-damping coefficients for the low-temperature region. The role of specific interference processes of phonon scattering at phonon-density fluctuations close to defects under conditions of weak interaction between the chains is analyzed. It is shown that, in the low-frequency region, where the dispersion law of the vibrational mode under consideration manifests quasi-one-dimensional properties, the renormalization of the thermal-conduction and sound-damping coefficients can be revealed experimentally when the atomic concentration of defects is $c⩾5%$⁠. The nonstandard temperature dependence of the speed of sound is discussed.