| Quantum-degenerate atomic Fermi gases provide a remarkable opportunity to study strongly interacting fermions. In contrast to other Fermi systems, such as superconductors, neutron stars or the quark-gluon plasma, these gases have low densities and their interactions can be precisely controlled over an enormous range. We will report on the recent observation of vortices in such a two-state mixture of fermionic atoms that provide definitive evidence for superfluidity. Scaled to the density of electrons in a solid, this new form of superfluidity would occur already above room temperature. In a subsequent study, we establish superfluidity for a broad range of population imbalances between the two spin states. We mapped out the superfluid regime as a function of interaction strength and population imbalance and characterized the quantum phase transition to the normal state, known as the Pauli limit of superfluidity. |
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