Supersolids are a strange quantum state of matter that combines...

Supersolids are a strange quantum state of matter that combines properties of solids and liquids.

Now they've gotten even more mind-bending, as scientists have transformed light itself into a supersolid. It's a breakthrough that could lead to new quantum and photonic technologies.

Beyond the everyday solids, liquids, gases, and plasmas, an entire zoo of exotic states of matter exists. Long theorized but only recently created, a supersolid has a crystalline structure like a regular solid, but it can also, counterintuitively, flow freely like a fluid.

"We can imagine the supersolid as a fluid composed of coherent quantum droplets periodically arranged in space," says atomic and optical physicist Iacopo Carusotto from the University of Trento in Italy.

The droplets, Carusotto explains, "are able to flow through an obstacle without undergoing perturbations, maintaining their spatial arrangement and mutual distance unchanged as happens in a crystalline solid."

Supersolids have previously only ever been made out of atoms, but the team led by scientists at the National Research Council (CNR) in Italy has now created one using photons for the first time.

"Realizing this exotic state of condensed matter in a fluid of light