Two electrons are better than one... In the Yb lab we produce Bose-Einstein condensates and degenerate Fermi gases of ytterbium atoms. These atoms offer metastable electronic states, ultranarrow clock transitions, multicomponent fermions with SU(N) interactions: a whole range of experimental tools that allow new possibilities for quantum simulation and quantum information processing.

Flavour-selective localization in interacting lattice fermions via SU(N) symmetry breaking

A large repulsion between particles in a quantum system can lead to their localization, an effect responsible for the Mott insulator phases in strongly correlated materials. In a system with multiple orbitals, an orbital-selective Mott insulator can form, where electrons in some orbitals are predicted to localize while others remain itinerant. Here we demonstrate a more general version of this phenomenon by observing flavour-selective localization in an atom-based quantum simulator. Our experiment realizes Fermi–Hubbard models with an SU(3) symmetry that can be broken using a tunable coupling between flavours. We observe an enhancement of the localization associated with a selective Mott transition and the emergence of flavour-dependent correlations. Our realization of flavour-selective Mott physics demonstrates the potential of cold atoms to simulate interacting multicomponent materials such as superconductors and topological insulators.

D. Tusi, et al.
Flavour-selective localization in interacting lattice fermions
Nat. Phys. 18, 1201 (2022)