Acoustic plasmons and anomalous thermal conductivity in high-temperature superconductors

The anomalies of the temperature dependence of thermal conductivity coefficient k(T) in high-temperature superconductors below the critical temperature Tc is supposed to be due to the weekly damped collective electronic Bose-type excitations with the acoustic dispersion law (acoustic plasmons) occurred inside the gap 2Δ. The << plasmonic >> mechanism of thermal conductivity allows one to explain the maximum of k(T) below Tc in the plane of the Cu O2 layers, the quadratic dependence k(T) approx T2 in the region T <<Tc, the depression of the maximum of k(T) anisotropy in the plane of the layers in the Y Ba2 Cu3 O7 crystal under normal-superconducting transition and so on