The cooling and trapping of atoms is one of the impressive
success stories in contemporary physics. After all, the
achievement of Bose-Einstein condensation has not just been the
finale to a tremendous effort but also the starting point for a
new chapter in many-body physics. The research now encompasses a
diverse range of topics including strongly correlated systems,
molecular and fermionic superfluids, as well as quantum
computation and precision measurements. Yet most of the
experiments have been performed with alkali atoms. Now, progress
made with elements containing two electrons in their outer
shell, such as helium or ytterbium (which could be called
“alkaline-earth-like” in analogy to the two-electron alkaline-
earth elements such as beryllium) is coming to fruition. In
Physical Review A, T. Fukuhura, S. Sugawa, M. Sugimoto, S. Taie,
and Y. Takahashi of Kyoto University, Japan, report their
observation of the transition from a superfluid to a Mott
insulating phase in a quantum degenerate gas of ytterbiu