Room-temperature supersolid quantum state created with light-matter hybrids

An international research team has observed a supersolid—a quantum state combining frictionless flow with crystal-like structure—in an exciton-polariton condensate at room temperature, a phenomenon previously only seen near absolute zero. The findings were published in Science Advances. The experiment used hybrid light-matter quasiparticles called exciton polaritons inside a liquid-crystal microcavity with an organic semiconductor, enabling strong coupling at temperatures up to 60°C. Researchers detected periodic density fringes and a spin helix, confirming spontaneous symmetry breaking, though measurements had to be completed within hours due to material reactivity. This breakthrough eliminates the need for cryogenic cooling in studying exotic quantum phases, potentially enabling ultrafast photonic devices, neuromorphic computing, and sensitive optical sensors. The liquid-crystal platform also offers the first electrically tunable system for investigating supersolid condensates, allowing dynamic control via external voltage for future quantum photonic technologies.