A repulsive atomic gas in a harmonic trap on the border of itinerant ferromagnetism

Understand

Alongside superfluidity, itinerant (Stoner) ferromagnetism remains one of the most well-characterized phases of correlated Fermi systems.

• A recent experiment has reported the first evidence for novel phase behavior on the repulsive side of the Feshbach resonance in a two-component ultracold Fermi gas.
• By adapting recent theoretical studies to the atomic trap geometry, we show that an adiabatic ferromagnetic transition would take place at a weaker interaction strength than is observed in experiment.
• This discrepancy motivates a simple non-equilibrium theory that takes account of the dynamics of magnetic defects and three-body losses.