Ultracold SU(N) fermions : multicolor physics and orbital magnetism
Mercredi 5 novembre 2014
à 11h en salle C. Brot
I will report on recent experiments performed at LENS with ultracold 173Yb Fermi gases. These two-electron atoms are characterized by a large nuclear spin and highly-symmetric interactions, which result in the possibility of performing quantum simulations of multi-component fermionic systems with intrinsic and tunable SU(N) interaction symmetry. By controlling the number of spin components N, we have studied how static and dynamic properties of strongly-correlated 1D liquids of 173Yb fermions change with N, evidencing for the first time intriguing effects caused by the interplay between interactions, low-dimensionality and quantum statistics .
In addition to their nuclear spin, two-electron fermions offer experimental access to supplementary degrees of freedom, in particular to long-lived electronically-excited states. By coherent control of the atomic state on the ultranarrow 1S0 – 3P0 clock transition, we have recently obtained the first demonstration of fast, coherent spin-exchange oscillations between two fermionic 173Yb atoms in two different electronic orbitals .
These experiments disclose some of the novel possibilities offered by two-electron atoms for quantum simulation, opening new directions connected e.g. to exotic quantum magnetism and to the investigation of many-body physics of systems with extended SU(N) symmetries.
 G. Pagano et al., A one-dimensional liquid of fermions with tunable spin, Nature Physics 10, 198 (2014).
 G. Cappellini et al., Direct observation of coherent inter-orbital spin-exchange dynamics, Phys. Rev. Lett. 113, 120402 (2014).
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