Ultracold Gases of Ytterbium: Ferromagnetism and Mott States in an SU(6) Fermi System

Understand

It is argued that ultracold quantum degenerate gas of ytterbium $^{173}$Yb atoms having nuclear spin $I = 5/2$ exhibits an enlarged SU$(6)$ symmetry.

• Within the Landau Fermi liquid theory, stability criteria against Fermi liquid (Pomeranchuk) instabilities in the spin channel are considered.
• Focusing on the SU$(n > 2)$ generalizations of ferromagnetism, it is shown within mean-field theory that the transition from the paramagnet to the itinerant ferromagnet is generically first order.
• On symmetry grounds, general SU$(n)$ itinerant ferromagnetic ground states and their topological excitations are also discussed.