New frontiers in ultracold quantum gases

Ultracold quantum gases at nanokelvin temperatures in the degenerate regime offer a rich playground for studying the fundamental behavior of interacting quantum matter, based on the exquisite control of experimental parameters and the possibility to tune the interparticle interactions. The results show novel phenomena and challenge theoretical descriptions of many-body quantum physics. After an introduction into the general ideas of the field, I will present examples from ongoing experimental research in Innsbruck. First, as an example related to condensed-matter physics, I will present the observation of quasi-particles in a degenerate Fermi gas, including the observations of “repulsive polarons”. Second, as an example connecting to nuclear physics, I will discuss the observation of “Efimov states”. Finally, as a most recent development, I will present the Bose-Einstein condensation of a new atomic species, atomic erbium featu- ring strongly anisotropic, dipolar interactions.