Ultracold gases, such as the Bose-Einstein condensates, can behave as fluids that exhibit the unusual rules of the quantum world. One striking example of this is superfluidity: flow without resistance.
At the JQI, we're currently building an apparatus to trap and cool Strontium atoms. Strontium has some nice atomic properties, which make it an ideal system to study. One main advantage is it has very narrow atomic transitions, which are relatively insensitive to electromagnetic surroundings.