Diffusive transport in spin-1 chains at high temperatures

We present a numerical study on the spin and thermal conductivities of the spin-1 Heisenberg chain in the high temperature limit, in particular, the Drude weight contribution and frequency dependence. We use the exact diagonalization and the recently developed microcanonical Lanczos method; it allows us a finite size scaling analysis by the study of significantly larger lattices. This work, pointing to a diffusive rather than ballistic behavior, is discussed with respect to other recent theoretical and experimental studies.