Researchers observe room-temperature supersolid in light-matter system
The experiment used hybrid particles in an electrically adjustable optical device, avoiding the extreme cooling required for ultracold-atom studies.
An international research team has reported creating a supersolid at room temperature using particles that combine light and matter. Published in Science Advances, the findings describe a quantum state that pairs crystal-like organization with the ability to flow without friction.
The TopoLight consortium used exciton polaritons, hybrid particles produced through strong interactions between light and matter. Its device combined a liquid crystal inside a small optical cavity with an organic semiconductor. Participants included the University of Warsaw, Poland's Military University of Technology, IBM Research Zurich and the French National Centre for Scientific Research (CNRS).
The researchers identified regularly spaced bright bands in light coming from the sample, indicating a repeating density pattern in the particle condensate. The bands shifted position between laser pulses, which the team interpreted as the system choosing among equivalent arrangements. A separate repeating pattern in the light's polarization showed another form of order occurring alongside the density pattern.
An applied voltage can change the device's optical properties. The researchers described it as the first electrically tunable platform for investigating supersolid exciton-polariton condensates. Possible applications include optical sensors and light-based computing, although these remain prospects for future research.
The experiment also faced a practical limit: the semiconductor gradually reacted with the liquid crystal, leaving only a few hours for measurements. Repeating measurements required making another sample. The key measurements were conducted at IBM Research Zurich.
