Dipolar Quantum Gases go Supersolid

Solids are rigid and liquids flow—a distinction that’s clear in our classical world. But this dichotomy breaks down at low temperatures where quantum effects prevail, allowing for a bizarre form of matter called a supersolid. This material’s atoms have the spatial periodicity of a crystal, yet they flow without friction. Fascinated with this idea, researchers have sought supersolidity for decades, first in helium, where experiments are ongoing, and then in quantum gases, where evidence of supersolidity was found in Bose-Einstein condensates (BECs) of atoms manipulated with light. Now three research teams have identified properties of a supersolid in what has long been considered one of the best places to look for it—BECs of atoms with large magnetic dipole moments [1–3].