Thermally condensing photons into a coherently split state of light

ORAL

Abstract

Techniques to control the quantum state of light play a crucial role in a wide range of fields, from quantum information science to precision measurements. While for electrons in solid state materials complex quantum states can be created by mere cooling, in the field of optics manipulation and control currently builds on non-thermodynamic methods. Using an optical dye-filled microcavity, we have demonstrated that photon wavepackets can be split through thermalization within a potential with two minima subject to tunnel coupling. Even at room temperature, photons condense into a quantum-coherent bifurcated ground state. Fringe signals upon recombination show the relative coherence between the two wells, demonstrating a working interferometer with the non-unitary thermodynamic beamsplitter.

In more recent work, we have started to study the effect of phase fluctuations from grand-canonical condensate properties due to coupling of photons to the photo-excitable dye molecules in the double well system. This effect becomes relevant for a large relative size of the dye reservoir. Current progress will be presented.

*We acknowledge funding from the Deutsche Forschungsgemeinschaft within SFB/TR 185, and the Cluster of Excellence ML4Q and the European Union within the European Research Council Advanced Grant project INPEC, the Quantum Flagship project PhoQuS, and the DLR project BESQ.

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Publication: C. Kurtscheid, D. Dung, E. Busley, F. Vewinger, A. Rosch, M. Weitz, Science 366, 894 (2019)
??C. Kurtscheid, D. Dung, A. Redmann, E. Busley, J. Klaers, F. Vewinger, J. Schmitt und M. Weitz, EPL 130, 54001 (2020)

Presenters

  • Christian Kurtscheid

    • Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany

Authors

  • Christian Kurtscheid

    • Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany

  • Andreas Redmann

    • Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany

  • David Dung

    • Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany

  • Erik Busley

    • Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany

  • Frank Vewinger

    • Univ Bonn
    • University of Bonn, Institute of Applied Physics
    • Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany

  • Achim Rosch

    • Univ Cologne
    • Institut für Theoretische Physik, Universität zu Köln, Zülpicher Str. 77, 50937 Cologne, Germany

  • Julian Schmitt

    • Univ Bonn
    • University of Bonn, Institute of Applied Physics
    • Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany

  • Martin Weitz

    • Univ Bonn
    • University of Bonn, Institute of Applied Physics
    • Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany
    • Bonn