Thermal Conductivity of Quasi-One-Dimensional Antiferromagnetic Spin-Chain Materials

We study heat transport in quasi-one-dimensional spin-chain systems by considering the model of one-dimensional bosonic spin excitations interacting with three-dimensional phonons and impurities in the limit of weak spin-lattice coupling and fast spin excitations. A combined effect of the phonon and impurity scatterings yields the following spin-boson thermal conductivity behavior: kappa_s ~ T^2 at low, kappa_s ~ 1/T at intermediate, and kappa_s = const at higher temperatures. Our results agree well with the existing experimental data for Sr2CuO3. We predict an unusual dependence on the impurity concentration for a number of observables and propose further experiments.
4+epsilon pages, 1 figure. Short story. Long story is cond-mat/0407257