A Supersolid Discovery: What We Know So Far

Have you ever heard of a solid that flows like a liquid? Scientists may have just discovered a new state of matter called supersolidity. If you are wondering what they are, supersolids are a peculiar state which combines superfluid and solid at the same time. Sound strange, right?

A few years ago, researchers found that certain ultracold gasses can exhibit the strange properties of both solids and liquids at the same time under certain conditions. This exciting discovery opened new possibilities for studying supersolidity and other exotic quantum states. While the most of us think of solids and liquids as distinct and separate phases of matter, these scientists showed that isn’t always the case.

Under certain circumstances, solid materials can take on liquid-like properties and flow without friction. The review published by researchers from CNR-INO in Nature Physics (DOI: https://doi.org/10.1038/s42254-023-00648-2) summarizes over 15 years of research uncovering how and why this strange phenomenon occurs. Thanks to this perspective focusing on the platform of dipolar gases, in which experiments have been able to map out a number of properties of the supersolid phase, we know a gas can behave like a solid.

While we now know supersolidity is possible, many open questions remain. Scientists aim to gain a better understanding of how supersolidity forms and its properties.

Begun over 50 years ago, supersolidity is now one of the most active research frontiers in the field of ultracold atoms, being possible on different platforms. These strange states of matter often lead to new insights and technologies we can’t even imagine yet. These supersolids may shape the future in some very unexpected ways. Science continues to surprise.

Read the review: Recati, A., Stringari, S. Supersolidity in ultracold dipolar gases. Nat Rev Phys (2023). https://rdcu.be/dn5Tx

Alessio Recati is a CNR Senior Researcher at the CNR-INO BEC Centre in Trento. He is a physicist whose research interests are mainly focused on the field of ultra-cold gases.

Sandro Stringari is an Italian theoretical physicist, who has contributed to the theory of quantum many-body physics, including atomic nuclei, quantum liquids and ultra-cold atomic Bose and Fermi gases. He is emeritus professor at the University of Trento.