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Quantum technologies

Dieter Meschede's research group
Home AMO physics colloquia
  • Prof. Mark Saffman

  • Invited speaker: Prof. Mark Saffman
    Affiliation: University of Wisconsin
    Title: Towards a 2D array of quantum gates with Rydberg atom interactions
    Time and room: 15:45, seminar room 1 in HISKP
    Abstract: I will review recent experiments on Rydberg state mediated entangling quantum gates. The long range nature of the Rydberg interaction appears promising for scaling to an array of fully interconnected quantum bits. I will discuss approaches based on single atom, as well as ensemble qubits, and present progress towards multi-qubit experiments.

  • Prof. Jakob Reichel

  • Invited speaker: Prof. Jakob Reichel
    Affiliation: ENS, Paris
    Title: Collective cavity QED with atomic Bose-Einstein condensates and exciton-polaritons
    Time and room: 15:00, seminar room 1 in HISKP

  • T. Kampschulte's defense

  • PhD defense: Tobias Kampschulte
    TitleCoherently driven three-level atoms in an optical cavity
    Time and room: 10:00, seminar room 1 in HISKP
  • Prof. Matthias Weidemüller

  • Invited speaker: Prof. Matthias Weidemüller
    Affiliation: Ruprecht-Karls-Universität Heidelberg
    Title: Rydberg Aggregates
    Time and room: 17 h c.t., lecture hall IAP
    Abstract: Due to the long-range character of the interaction between highly excited atoms, the dynamics of an ultracold gas of Rydberg atoms is entirely determined by van-der-Waals and dipole-dipole interactions. One outstanding property is the tunability of the strength and the character of the interactions with static electric fields. This allows one to explore the transition from a weakly coupled two-body system to a strongly coupled many-body system. The long-range interaction leads to many-body entanglement and has possible applications in quantum computing. In my talk I will first give a general introduction into the field of Rydberg gases with special emphasis on our recent experiments.

  • Prof. Hanns-Christoph Nägerl

  • Invited speaker: Prof. Hanns-Christoph Nägerl
    Affiliation: Universität Innsbruck
    Title: Strongly correlated one-dimensional quantum systems
    Time and room: 17 h c.t., lecture hall IAP
    Abstract: I will review our recent experiments with atomic quantum gases in the regime of quantum degeneracy, Bose-Einstein condensation, and strong correlations. Ultracold atomic gases are versatile tunable laboratory systems for the study of complex many-body quantum phenomena as essentially all parameters such as geometry and strength of confinement and the strength of interactions [1] can be controlled with near-perfect isolation from external perturbations. For atoms 1D geometry, I will discuss the strongly-interacting limits of so-called Tonks-Girardeau and super-Tonks-Girardeau phases [2]. We observe the “pinning” quantum phase transition in the presence of an arbitrarily weak lattice potential [3]. Exploiting three-body recombination processes, we determine the value of the three-particle correlation function at the origin from weak to strong interactions [4]. I will finally discuss measurements of impurity transport through a strongly interacting 1D system.

    [1] E. Haller et al., Phys. Rev. Lett. 104, 153203 (2010); [2] E. Haller et al., Science 325, 1224 (2009); [3] E. Haller et al., Nature 466, 597 (2010); [4] E. Haller et al., manuscript in preparation.