Degenerate Fermi Gases of Erbium Atoms

The project combines the expertise of the applicant in the field of narrow-linewidth laser sources and of complex level structures with the one available at the University of Innsbruck in the domain of ultracold Fermi gases. The project proposes to realize for the first time degenerate Fermi gases of erbium atoms. The strong dipole-dipole interaction (DDI) available with erbium atoms, which possess a large magnetic moment of 7 Bohr magneton, can significantly impact few- and many-body physics. DDI has a long-range and anisotropic character and is expected to give rise to exotic quantum phases with spatial orders as well as anisotropic collisional processes. The project has three main goals. First, we propose to realize a degenerate Fermi gas of erbium atoms. The main difficulty here is that evaporative cooling does not work efficiently with identical fermions. To overcome this fundamental limitation, we plan to test two strategies. One is based on elastic collisions introduced by DDI, while the other relies on a conventional strategy that uses elastic collisions in a spin mixture. The second project goal is to investigate dipolar few-body physics in both single- and two-component gases. The elastic and inelastic collisional processes are expected to show universal scattering rates that are solely determined by the dipole moment and by the atomic mass. In two-component gases, we will perform Feshbach spectroscopy and create strongly magnetic Feshbach molecules via magnetoassociation at a FR. The third project goal is to investigate many-body physics emerging with DDI in a gas of strongly magnetic molecules and in a two-component Fermi gas. Strongly magnetic molecules are expected to exhibit exotic quantum states such as supersolid, checkerboard, and self-assembled chain. In a two-component Fermi gas, we will investigate the impact of DDI on BCS-BEC crossover physics. DDI is expected to significantly deform the Fermi surface and to induce a competition between singlet- and triplet pairing.