Kirankumar Karkihalli Umesh, Julian Schulz, Julian Schmitt, Martin Weitz, Georg von Freymann, Frank Vewinger: Â
🔓 arXiv:2311.10485 (2023)
We experimentally study the properties of a harmonically trapped photon gas undergoing Bose-Einstein condensation along the dimensional crossover from one to two dimensions. The photons are trapped inside a dye microcavity, where polymer nanostructures provide a harmonic trapping potential for the photon gas. By varying the aspect ratio of the trap we tune from an isotropic two-dimensional confinement to an anisotropic, highly elongated one-dimensional trapping potential. Along this transition, we determine caloric properties of the photon gas, and find a softening of the second-order Bose-Einstein condensation phase transition observed in two dimensions to a crossover behaviour in one dimension.