ABSTRACT
Bose-Einstein condensation has been observed in several physical systems, including cold atomic gases, quasiparticles in solid state systems as polaritons, and magnons. Photons usually show no Bose-Einstein condensation, since for Planck’s blackbody radiation the particle number is not conserved and the photons at low temperatures vanish in the system walls. I here describe experiments with a dye-filled optical microresonator experimentally observing Bose-Einstein condensation of photons. Thermalization is achieved in a number conserving way by repeated absorption re-emission cycles on the dye molecules, and the cavity mirrors provide both an effective photon mass and a confining potential. More recently, we have investigated the coherence of the photon gas. In other work, lattice potentials for photons in the dye microcavity have been realized. In my talk, I will begin with a general introduction and give an account of current work and future plans of the Bonn photon gas experiment.
BIOGRAPHY
Prof Martin Weitz is a Professor of Experimental Physics at the University of Bonn in Germany. He received his PhD from the University of Munich for work on precision spectroscopy of atomic hydrogen under supervision of Prof. T. W. Hänsch. After a postdoctoral stay at Stanford University and joining the Max Planck Institute of Quantum Optics in Garching he became professor at the University of Tübingen in 2001. Since 2006 he is professor at the University of Bonn. His current research is focused on equilibrium thermodynamics of light, quantum physics of ultracold atomic gases, and novel laser cooling techniques.
Date & Time
Venue
Chair