# Université Clermont Auvergne team reports supersolid phase in light-matter polaritons at room temperature - Published: 2026-11-05 00:10 UTC - Section: Science › Physics - Tags: supersolid, exciton polaritons, light-matter hybrids, optical microcavity, liquid crystal, Bose-Einstein condensate, spontaneous symmetry breaking, quantized vortices, spin helix, Science Advances - URL: https://realtech.media/news/rt-3a9ed956162ef8d03e0cc284_universit_clermont_auvergne/ **Exciton polaritons in an organic microcavity with liquid crystal showed stripes and vortices at room temperature; the superfluid part still needs quantitative checks.** ![Université Clermont Auvergne team reports supersolid phase in light-matter polaritons at room temperature](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/eeb48d57dae51ddf.webp) *scinexx* Researchers at Université Clermont Auvergne (UCA) led by Prof. Guillaume Malpuech have observed signs of a supersolid phase in a mixture of light and matter at room temperature, scinexx reports. The experiment used an optical microresonator and was published in Science Advances. A supersolid combines a crystal-like periodic density with superfluid properties, and such states were until now created mostly in extremely cold atomic gases. [1] ## Microcavity with liquid crystal In the device, light is confined between mirror layers and coupled to excitations of an organic semiconductor. This produces short-lived light-matter quasiparticles, exciton polaritons, some of which can form a Bose-Einstein condensate already at room temperature. [1] An added liquid crystal lets an applied voltage change the properties of the confined light, so the system has two energetically equivalent states in which polaritons accumulate. [1] Prof. Wiktor Piecek of the Wojskowa Akademia Techniczna (WAT) said the microcavities can operate at about 60 degrees Celsius. The strong light-matter coupling needed for the experiment works without elaborate cooling. [1] ## Stripes, vortices and limits After excitation with short laser pulses, the emitted light showed regularly spaced bright and dark stripes. They reveal a periodic density in the condensate, although the sample has no preset stripe pattern; the order arises from the superposition of two equivalent states. [1] In individual pulses the stripes appeared at different positions rather than following a fixed irregularity of the sample, which points to spontaneous symmetry breaking. At weaker excitation, the stripe position stayed more strongly pinned by material irregularities. [1] The team also saw a regular change in the polarization of the light, a spin helix. Two spatial orders therefore appeared at once, distinguishable by intensity and polarization. In about ten percent of individual experiments, stripe dislocations appeared that correspond to quantized vortices in the condensate. [1] According to the report, the shifting stripes at high particle density and the vortices support the interpretation as a supersolid phase. The experiment did not directly measure frictionless flow past an obstacle. Additional simulations support the interpretation, but a full characterization of the superfluidity requires further quantitative studies. [1] The work was difficult in practice: the organic semiconductor reacted with the liquid crystal, and sample properties changed over time. First author Dr. Marcin Muszyński said that repeating a measurement required a completely new sample. The stability of the microresonators and the fluid properties of the condensate still have to be examined before use in optical circuits or sensors. [1] ## Sources 1. [scinexx](https://www.scinexx.de/news/physik/licht-materie-hybride-bilden-bei-raumtemperatur-einen-supersoliden-quantenzustand) --- Source: RealTech, realtech.media — https://realtech.media/news/rt-3a9ed956162ef8d03e0cc284_universit_clermont_auvergne/