Researchers at Rensselaer Polytechnic Institute (RPI) have created a new and unusual state of matter—known as a supersolid—by engineering how light and matter interact inside a nanoscale device. The work, published in Nature Nanotechnology, demonstrates that this exotic quantum phase can exist at room temperature, overcoming a long-standing limitation in the field.

Supersolids are unusual because they combine two seemingly incompatible properties: Like a solid, they form an ordered, crystal-like structure. At the same time, they behave like a fluid, meaning they can flow without resistance. Until now, such states have only been observed under extremely cold conditions, close to absolute zero.

“Our work shows that you can create and control this exotic state using light,” said Wei Bao, Ph.D., assistant professor in the Department of Materials Science and Engineering at RPI and senior author of the study. “What’s especially exciting is that it happens at room temperature, in a platform that can be engineered and potentially scaled.”