title: Spin transport in a one-dimensional anisotropic Heisenberg model.
abstract: We analytically and numerically study spin transport in a one-dimensional Heisenberg model in linear-response regime at infinite temperature. It is shown that as the anisotropy parameter Δ is varied spin transport changes from ballistic for Δ<1 to anomalous at the isotropic point Δ=1, to diffusive for finite Δ>1, ending up as a perfect isolator in the Ising limit of infinite Δ. Using perturbation theory for large Δ a quantitative prediction is made for the dependence of diffusion constant on Δ.
authors.affiliation: Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
authors.forename: Marko
authors.initials: M
authors.lastname: Znidarič