Diffusion cascade in a model of interacting random walkers
Phys. Rev. B 114, 014312 – Published 20 July, 2026
DOI: https://doi.org/10.1103/93zy-gq3t
Abstract
We consider the relaxation of finite-wave-vector density waves in a facilitated classical lattice gas. Linear hydrodynamics predicts that such perturbations should relax exponentially, but nonlinear effects were predicted to cause subexponential relaxation via nonperturbative long-time tails [L. V. Delacretaz, SciPost Phys. 9, 034 (2020)]. We present a detailed numerical study of this effect. While our results clearly indicate the importance of nonlinear effects, we find that the wave vector dependence of the late-time relaxation is clearly inconsistent with theoretical predictions. We discuss manifestations of hydrodynamic nonlinearities in mesoscopic samples and at short times.
