title: Heat Transport in Spin Chains with Weak Spin-Phonon Coupling.
abstract: The heat transport in a system of S=1/2 large-J Heisenberg spin chains, describing closely Sr(2)CuO(3) and SrCuO(2) cuprates, is studied theoretically at T≪J by considering interactions of the bosonized spin excitations with optical phonons and defects. Treating rigorously the multiboson processes, we derive a microscopic spin-phonon scattering rate that adheres to an intuitive picture of phonons acting as thermally populated defects for the fast spin excitations. The mean-free path of the latter exhibits a distinctive T dependence reflecting a critical nature of spin chains and gives a close description of experiments. By the naturalness criterion of realistically small spin-phonon interaction, our approach stands out from previous considerations that require large coupling constants to explain the data and thus imply a spin-Peierls transition, absent in real materials.
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Chernyshev
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.|Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, Moscow 125412, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Rozhkov