Publication:
Fahri Emre Öztürk, Frank Vewinger, Martin Weitz, and Julian Schmitt
Fluctuation-Dissipation Relation for a Bose-Einstein Condensate of Photons
Phys. Rev. Lett. 130, 033602 (2023)
Fluctuation-Dissipation-Theorem confirmed for Bose-Einstein condenstaes Our paper on the fluctuation-dissipation theorem appears in PRL
The grand-canonical coupling of photons to a bath of dye molecules leads to fluctuations of the particle number. According to the fluctuation-dissipation theorem this is connected to a viscosity of the photon gas. In our experiment, we were able to prove the relation for a Bose-Einstein condesed gas for the first time.
Experimental setup and origin of the fluctuations
- View at the experiment: The photons are trapped between two mirrors, and interact with the dye molecules, visible by the orange fluorescence. From the statistics of the outcoupled light we can determine the fluctuations. The fluctuations result from the interconversion of photons and excited dye molecules and vice versa (Inset).
© J. Schmitt/Uni Bonn
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