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Quantum technologies

Dieter Meschede's research group
Home AMO physics colloquia
  • Dr. Stefan Kuhr

  • Invited speaker: Dr. Stefan Kuhr
    Affiliation: MPI für Quantenoptik, Garching
    Title: Single-site-resolved Detection and Manipulation of Atoms in an Optical Lattice
    Time and room: 17:15, lecture hall IAP
  • Stefan Brakhane

  • Diplom-Kolloquium: Stefan Brakhane
    Title: Control of Atom-Cavity Coupling using Feedback
    Time and room: 15:15, lecture hall IAP
  • Prof. Michael Drewsen

  • Invited speaker: Prof. Michael Drewsen
    Affiliation: University of Aarhus
    Title: Ion Coulomb Crysal Based Cavity QED Experiments
    Time and room: 09:15, lecture hall IAP
  • Prof. Daniel Hägele

  • Invited speaker: Prof. Daniel Hägele
    Affiliation: Universität Bochum
    Title: Neues von der Photolumineszenz
    Time and room: 17:15, lecture hall IAP

  • Prof. C. Chin

  • Invited speaker: Prof. Chen Chin
    Affiliation: Chicago University
    Title: Observation of Scale Invariance and Universality in Two-Dimensional Quantum Gases
    Time and room: 17:15, lecture hall IAP
    Abstract: The collective behavior of a many-body system near a continuous phase transition is insensitive to the details of its microscopic physics. Characteristic features near the phase transition, called critical phenomena, are that the thermodynamic observables follow generalized scaling laws. The Berezinskii-Kosterlitz-Thouless (BKT) phase transition in two-dimensional Bose gases, for example, presents a particularly interesting case because the marginal dimensionality and intrinsic scaling symmetry result in a broad fluctuation regime which manifests itself in an extended range of scale invariant and universal behavior. We report the observation of a global invariance of scale and a universal description of 2D gases based on direct in situ optical imaging. The extracted universal thermodynamic functions confirm the wide critical regime near the BKT phase transition, provide a sensitive test to Monte Carlo calculations, and point toward a growing density-density correlations in the critical regime. Our observation raises new perspectives to explore further universal phenomena in the realm of quantum critical physics near a quantum phase transition.

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