01315nas a2200145 4500008004100000245007600041210006900117260001400186520084500200100002201045700002701067700002001094700001801114856003701132 2021 eng d00aSubdiffusive hydrodynamics of nearly-integrable anisotropic spin chains0 aSubdiffusive hydrodynamics of nearlyintegrable anisotropic spin c9/27/20213 a
We address spin transport in the easy-axis Heisenberg spin chain subject to integrability-breaking perturbations. We find that spin transport is subdiffusive with dynamical exponent z=4 up to a timescale that is parametrically long in the anisotropy. In the limit of infinite anisotropy, transport is subdiffusive at all times; for large finite anisotropy, one eventually recovers diffusion at late times, but with a diffusion constant independent of the strength of the integrability breaking perturbation. We provide numerical evidence for these findings, and explain them by adapting the generalized hydrodynamics framework to nearly integrable dynamics. Our results show that the diffusion constant of near-integrable interacting spin chains is not generically a continuous function of the integrability-breaking parameter.
1 aDe Nardis, Jacopo1 aGopalakrishnan, Sarang1 aVasseur, Romain1 aWare, Brayden uhttps://arxiv.org/abs/2109.13251