Atom Loss Maximum in Ultra-cold Fermi Gases

Understand

Recent experiments on atom loss in ultra-cold Fermi gases all show a maximum at a magnetic field below Feshbach resonance, where the s-wave scattering length is large (close to inter-particle distance) and positive.

• These experiments have been performed over a wide range of conditions, with temperatures and trap depths spanning over three decades.
• Different groups have come up with different explanations, among them the emergence of Stoner ferromagnetism.
• Here, we show that this maximum is a consequence of two major steps.