2011/03/31 by Marko Znidaric · 1 citation
Physics and Astronomy · #cond-mat.str-el #quant-ph
paper · pdf · doi:10.1103/physrevlett.106.220601
published as Phys. Rev. Lett. 106, 220601 (2011) · 5 pages, 4 figures; v2.: few comments added and typos corrected; published version
arxiv created 2011/06/02 · arxiv updated 2011/06/03
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 Delta is varied spin transport changes from ballistic for Delta<1 to anomalous at the isotropic point Delta=1, to diffusive for finite Delta>1, ending up as a perfect isolator in the Ising limit of infinite Delta. Using perturbation theory for large Delta a quantitative prediction is made for the dependence of diffusion constant on Delta.