Dr. Frank Vewinger
Rheinische Friedrich-Wilhelms-Universität Bonn
Título: Bose-Einstein condensation of photons: A highly subjective journey through statistical physics
Resumen: The ideal Bose gas is textbook physics, however experimental realizations are problematic due to the ever-present interactions. This has changed with the advent of thermalized photons trapped in a microcavity, where interactions are significantly weaker than in atomic or polaritonic systems. In this optical quantum gases, near-equilibrium physics can be studied in the presence of a reservoir, and with controllable dissipation, making Bose-Einstein condensates of photons a versatile platform.
Experimentally, dye-filled microcavities are employed to achieve thermalization in a number conserving way by repeated absorption re-emission cycles on the dye molecules. The latter thus provide both a heat and a particle reservoir, and depending on the size of the molecular reservoir the statistics can cross from canonical to grand canonical. By shaping the mirrors, trapping potentials for photons can be realized, which allows to study statistical physics in arbitrary potentials. Moreover, as the photons are lost through the mirrors and correspondingly have to be replaced by pumping the cavity, our system is a prototypical platform for driven-dissipative systems, with tunable dissipation from a closed to an open system.
In my talk, I will begin with a general introduction of this versatile platform, and then describe a few experiments that highlight the versatility of the platform, such as our experiments on the 'particle in a box' or the influence of the grand canonical statistics on the system properties. I will conclude by pointing out future directions for this versatile platform.
