Probing Ferromagnetic Order In Few-Fermion Correlated Spin-Flip Dynamics

We Unravel The Dynamical Stability Of A Fully Polarized One-Dimensional Ultracold Few-Fermion Spin-1/2 Gas Subjected To Inhomogeneous Driving Of The Itinerant Spins. Despite The Unstable Character Of The Total Spin-Polarization The Existence Of An Interaction Regime Is Demonstrated Where The Spin-Correlations Lead To Almost Maximally Aligned Spins Throughout The Dynamics. The Resulting Ferromagnetic Order Emerges From The Build Up Of Superpositions Of States Of Maximal Total Spin. They Comprise A Decaying Spin-Polarization And A Dynamical Evolution Towards An Almost Completely Unpolarized NOON-Like State. Via Single-Shot Simulations We Demonstrate That Our Theoretical Predictions Can Be Detected In State-Of-The-Art Ultracold Experiments.