Supersolids reach the second dimension
"Supersolid" matter can simultaneously form a crystal and flow without friction. The first two-dimensional supersolid has now been produced using ultracold gases made of strongly magnetic atoms.

Although the Latin prefix "supra" means something like "above", materials in a state referred to as supersolid are not particularly rigid. Rather, they combine the ordered structure of a solid with the properties of a so-called superfluid. This is a substance that flows completely without friction. You can think of a supersolid as an ice cube that is immersed in liquid water, which flows through it without encountering any resistance.
For the first time, supersolids were produced independently by three research groups in 2019. A team led by Francesca Ferlaino from the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences in Innsbruck, one led by Giovanni Modugno from the University of Florence and one led by Tilman Pfau from the University of Stuttgart used ultracold, magnetically interacting atoms. However, the structure in the experiments was only ordered along one dimension. Now Matthew Norcia and Claudia Politi from the Innsbruck institute have created a two-dimensional supersolid from ultracold dysprosium atoms …