Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
Phys Rev Lett. 2016 Jan 8;116(1):017204. doi: 10.1103/PhysRevLett.116.017204.
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.
我们对 S=1/2 大-J 海森堡自旋链系统中的热输运进行了理论研究，该系统描述了紧密 Sr(2)CuO(3) 和 SrCuO(2) 铜酸盐，在 T≪J 的情况下通过考虑玻色化自旋激发与光学声子和缺陷的相互作用来进行研究。通过严格处理多玻色子过程，我们推导出了微观自旋-声子散射率，该散射率符合声子作为快速自旋激发的热填充缺陷的直观图像。后者的平均自由程表现出独特的 T 依赖性，反映了自旋链的临界性质，并对实验进行了很好的描述。根据实际小自旋-声子相互作用的自然标准，我们的方法与以前的考虑不同，以前的考虑需要大的耦合常数来解释数据，因此意味着在实际材料中不存在自旋-佩尔斯转变。
