Acoustic plasmons as a possible cause of the anomalous thermal conductivity peak in high-Tc superconductors below the critical temperature

It is shown that the anomalies in the temperature dependence of the thermal conductivity κ(T) in high-Tc superconductors below the critical superconducting transition temperature Tc are attributable to the existence of slowly damped Bose-type collective electron excitations with an acoustic dispersion law (acoustic plasmons) within the gap 2 triangle(T). This open-quotes plasmonclose quotes heat-conduction mechanism in layered cuprate metal oxide compounds accounts for the anomalous peak of κ(T) in the plane of the CuO2 layers, the quadratic dependence κ(T) ∝ T2 for T much-lt Tc, the suppression of the maximum of κ(T) at T∼Tc/2 by allovalent impurities and a magnetic field, the reversal of the anisotropy of κ(T) in the plane of the layers in single-domain YBa2Cu3O7-ε crystals with ordered CuO chains in the transition from the normal state to the superconducting state, etc. 52 refs., 4 figs