TY - JOUR T1 - Subdiffusive hydrodynamics of nearly-integrable anisotropic spin chains Y1 - 2021 A1 - Jacopo De Nardis A1 - Sarang Gopalakrishnan A1 - Romain Vasseur A1 - Brayden Ware AB -

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. 

UR - https://arxiv.org/abs/2109.13251 ER -