Heat transport by lattice and spin excitations in the spin-chain compoundsSrCuO2 and Sr2CuO3 - art. no. 054412

We present the results of measurements of the thermal conductivity of the q uasi-one-dimensional S = 1/2 spin-chain compound SrCuO2 in the temperature range between 0.4 and 300 K along the directions parallel and perpendicular to the chains. An anomalously enhanced thermal conductivity is observed al ong the chains above about 40 K. The analysis of the present data and a com parison with analogous recent results for Sr2CuO3 and other similar materia ls demonstrates that this behavior is generic for cuprates with copper-oxyg en chains and strong intrachain interactions. The observed anomalies are at tributed to the one-dimensional energy transport by spin excitations (spino ns), limited by the interaction between spin and lattice excitations. The e nergy transport along the spin chains has a nondiffusive character, in agre ement with theoretical predictions for integrable models.