ERBIUM · Ultracold Erbium: Exploring Exotic Quantum Gases

Ultracold quantum gases have exceptional properties and offer an ideal test-bed to elucidate intriguing phenomena of modern quantum physics. My project proposes to use a new exotic element to study strong dipolar effects in quantum gases. For its appealing properties, we choose erbium (Er), a rare-earth metal that has hardly been explored until now. This species is strongly magnetic and comparatively heavy. Due to these characteristics, we expect the quantum system to be of extreme dipolar character and to exhibit a large number of magnetic Feshbach resonances, necessary to manipulate the low-energy scattering properties. Moreover, this element has a very rich energy level spectrum, which could open up the way to establish novel laser cooling schemes, and it has numerous isotopes, one of them having a fermionic character. Remarkably, none of the species so far used in ultracold quantum gas experiments offers such a unique combination of properties! By using Erbium, we will be in an optimal position to produce a strongly dipolar atomic gases of bosons and fermions with tunable contact interaction. First important goals of the ERBIUM project include: Extensive study of Er scattering properties, realization of the first Bose-Einstein condensates and degenerate Fermi gases of erbium atoms, study of dipolar effects in atomic system, production of strongly polar weakly-bound Er molecules and study their properties in a two-dimensional trapping environment. We also have a long-term vision for the ERBIUM project: we will mix heavy erbium atoms with much lighter lithium atoms to produce atomic mixtures with extreme mass imbalance.