We report on the first direct observation of fast spin-exchange coherent oscillations between different long-lived electronic orbitals of ultracold ¹⁷³Yb fermions. We measure, in a model-independent way, the strength of the exchange interaction driving this coherent process. This observation allows us to retrieve important information on the inter-orbital collisional properties of ¹⁷³Yb atoms and paves the way to novel quantum simulations of paradigmatic models of two-orbital quantum magnetism.

G. Cappellini et al.,
Direct Observation of Coherent Interorbital Spin-Exchange Dynamics
Phys. Rev. Lett. 113, 120402 (2014)

See also the Physics Viewpoint by A. M. Rey:

A. M. Rey
Observing the Great Spin and Orbital Swap
Physics 7, 95 (2014)

In an array of one-dimensional traps, we create impurities of K atoms immersed in reservoir of Rb atoms. The impurities are first localized by an external species-selective potential and then suddenly freed: their subsequent dynamics exhibits "breathing" oscillations, due to a weaker confining potential. We find that the amplitude of these oscillations is reduced when increasing the strength of the impurity-reservoir interaction, irrespective of its sign. We interpret our data with a polaric mass shift model derived following Feynman variational approach.

J. Catani et al.
Quantum dynamics of impurities in a one-dimensional Bose gas
Phys. Rev. A 85, 023623 (2012)

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)