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.

1d fermions in multicolor!

Correlations in systems with spin degree of freedom are at the heart of fundamental phenomena, ranging from magnetism to superconductivity. The effects of correlations depend strongly on dimensionality, a striking example being one-dimensional (1D) electronic systems, extensively studied theoretically over the past fifty years. However, the experimental investigation of the role of spin multiplicity in 1D fermions — and especially for more than two spin components — is still lacking. Here we report on the realization of 1D, strongly correlated liquids of ultracold fermions interacting repulsively within SU(N) symmetry, with a tunable number N of spin components. We observe that static and dynamic properties of the system deviate from those of ideal fermions and, for N > 2, from those of a spin-1/2 Luttinger liquid. In the large-N limit, the system exhibits properties of a bosonic spinless liquid. Our results provide a testing ground for many-body theories and may lead to the observation of fundamental 1D effects.

G. Pagano et al.,
A One-Dimensional Liquid of Fermions with Tunable Spin
Nature Phys. 10, 198 (2014)