Phys. Rev. Lett. 104, 063001 (2010)

Physicists have trapped the first ultracold gas of dysprosium, prized for being one of the most magnetic atoms in the periodic table.

Using lasers and magnets to cool and trap atoms is easiest in atoms that have only a few electrons whirling around. But cooling dysprosium, which has many electrons, was thought to be near impossible. However, with the aid of a powerful blue laser, Mingwu Lu and his colleagues at the University of Illinois at Urbana-Champaign cooled half a billion dysprosium atoms to below 3 millikelvin, bringing them close to a standstill.

The authors suggest that, cooled a little further, dysprosium could spontaneously form new phases of quantum matter akin to the patterns seen in liquid crystals.