810. WE-Heraeus-Seminar — Condensates of Light

Bose-Einstein condensation has in the last thirty years been observed in several physical systems, including cold atomic gases and exciton-polaritons, which are mixed states of matter and light in solid state systems. Other than massive particles photons usually do not exhibit Bose-Einstein condensation despite having bosonic nature, the background being that in blackbody radiation, as the textbook example for a photonic gas, the chemical potential vanishes, and at low temperature photons vanish instead of exhibiting condensation. More recently, Bose-Einstein condensations of photons has been observed in low-dimensional systems, e.g. by confining light in dye-solution filled optical microresonators, the use of plasmonic nanoparticle arrays or erbium-doped fiber cavities. Quantum fluids of light have allowed for the observation of novel quantum liquid effects, both in the regimes of near and partial thermal equilibrium. The seminar will illuminate the different platforms and the effects observed in this rapidly evolving field.