Universal spin-mixing oscillations in a strongly interacting one-dimensional Fermi gas

We study the spin-mixing dynamics of a one-dimensional strongly repulsive Fermi gas under harmonic confinement. By employing a mapping onto an inhomogeneous isotropic Heisenberg model and the symmetries under particle exchange, we follow the dynamics until very long times. Starting from an initial spin-separated state, we observe superdiffusion, spin-dipolar large amplitude oscillations, and thermalization. We report a universal scaling of the oscillations with particle number N-1/4. Our Letter puts forward one-dimensional correlated fermions as a different system to observe the emergence of nonequilibrium universal features.