Hydrodynamic Diffusion in Integrable Systems

Understand

We show that hydrodynamic diffusion is generically present in many-body interacting integrable models.

• We extend the recently developed generalised hydrodynamic (GHD) to include terms of Navier-Stokes type which lead to positive entropy production and diffusive relaxation mechanisms.
• These terms provide the subleading diffusive corrections to Euler-scale GHD for the large-scale non-equilibrium dynamics of integrable systems, and arise due to two-body scatterings among quasiparticles.
• We give exact expressions for the diffusion coefficients.