# Calendar of Physics Talks Vienna

 Sandwich cavities for efficient single photon sources
 Speaker: Pradyumna Paranjape (Synthetic Quantum Systems Kirchhoff Institute For Physics Heidelberg) Abstract: Electromagnetic environment around a quantum emitter can be modified by introducing plasmonic nanocavities around it. Inside such cavities, the density of radiating modes is enhanced. In this presentation, I will talk about our cavity design which was implemented to realise Purcell-enhanced single photon emission from nitrogen-vacancy (NV) centres in nanodiamonds by coupling them to a monolithic nanocavity with a small mode volume. Date: Mon, 27.03.2017 Time: 11:00 Location: Atominstitut, Bibliothek Contact: J. Schmiedmayer

 Introduction to Poisson Lie-groups
 Speaker: Prof. Catherine Meusburger (U Erlangen) Abstract: A Poisson-Lie group is a Lie group that is also a Poisson manifold in such a way that the multiplication is a Poisson map. On the Lie algebra level, this implies that the dual vector space of its Lie algebra also has a Lie algebra structure, and the two Lie algebra structures satisfy a compatibility condition. This is called a Lie bialgebra and can be viewed as the infinitesimal counterpart of a quantum group. Hence, we can interpret Lie-bialgebras as the infinitesimal counterparts and Poisson-Lie groups as the classical counterparts of quantum groups. I explain these relations and then discuss Poisson actions of Poisson-Lie groups on Poisson manifolds. I explain why these structures can be expected to appear in gauge theory. If there is time, I also cover Drinfeld's classification of Poisson homogeneous spaces, i.e. Poisson manifolds with transitive Poisson actions of Poisson-Lie gr Date: Mon, 27.03.2017 Time: 15:15 Duration: 60 min Location: Erwin Schrödinger International Institute, Boltzmanngasse 9, 1090 Wien, Boltzmann lecture hall Contact: secr@esi.ac.at

 CoQuS Colloquium Seminar Talk by Alexander L. Gaeta
 Speaker: Alexander L. Gaeta (OSA & Future Technology, CoQuS) Abstract: Research has shown that the properties of a light beam can be manipulated to perform ultrafast all-optical signal processing in the time domain. I will describe our work that uses nonlinear optics to create temporal lenses that can magnify, compress, and Fourier transform optical waveforms in the time domain and show that such manipulation can be extended to the quantum domain. Through use of more exotic lenses, temporal gaps in light beams can be opened and closed which can be used to cloak events over short periods of time. Date: Mon, 27.03.2017 Time: 16:00 Duration: 120 min Location: Kontaktraum, 6th Floor, Gußhausstraße 27-29, 1040 Vienna Contact: CoQuS Team

 Simulation of Processes @ quasi-2D Interfaces by ab initio MD
 Speaker: Dr. Marcella Iannuzzi (Universität Zürich) Abstract: The modelling of nanostructures by means of atomistic simulations, often based on density functional theory, has become a key ingredient to gain insight on the properties of fascinating and complex new materials. Such theoretical studies are often able to highlight aspects that successively can be exploited to design new systems and to advance their application. Since long, our research activity has been dedicated to the development and improvement of suitable computational protocols to address the always new challenging questions that keep arising from the experimental side. We specialized, in particular, on quasi two dimensional materials formed at the surface of crystalline solids, and on their interaction with atoms, clusters, or molecules. Thanks to the input received from the close collaboration with different experimental groups and also investing in the constant further developme Date: Tue, 28.03.2017 Time: 16:00 Location: Technische Universität Wien, Institut für Angewandte Physik, E134 yellow tower „B“, 5th floor, Sem.R. DB gelb 05 B (room DB05L03), 1040 Wien, Wiedner Hauptstr. 8-10 Contact: Univ.Prof. Dr. Ulrike Diebold

 Continuum dynamics on manifolds: Applications to Elasticity of Residually-Stressed Bodies
 Speaker: Elik Olami (Jerusalem) Abstract: In this talk we discuss the dynamics of continua on differentiable manifolds. We present a covariant derivation of equations of motion, viewing motion as a curve in the infinite-dimensional Banach manifold of embeddings of a body manifold in a space manifold. Our main application is the motion of residually- stressed elastic bodies; residual stress results from a geometric incompatibility between body and space manifolds. We then study a particular example of elastic vibrations of a two- dimensional curved annulus embedded in a sphere. Based on a joint work with Raz Kupferman and Reuven Segev. Date: Wed, 29.03.2017 Time: 13:00 Duration: 60 min Location: Arbeitsgruppe Gravitation, Währinger Strasse 17, common room, 1. Stock Contact: P.T. Chrusciel

 Discrete Spacetime Phenomenology
 Speaker: Alessio Belenchia (University of Vienna) Abstract: This talk focuses on several instances of spacetime phenomenology using low‐energy systems. In particular, the phenomenology related to non‐local kinetic operators will be addressed. This type of non‐locality occurs in different models of quantum spacetime and, in Causal set quantum gravity, can be seen as a direct consequence of discreteness and Lorentz Invariance. After a brief introduction of the object of, and motivations behind, our studies, there response of an inertial Unruh‐DeWitt detector coupled to a non‐local scalar field will be considered to show that this system is quite sensitive to the non‐locality scale. The evolution of coherent states of a harmonic oscillator subject to kinematic non‐locality will then be discussed, pointing out the characteristic effects to be looked for in optomechanical experiments. Finally, the possible experimental constraints on the … Date: Wed, 29.03.2017 Time: 14:15 Location: TU Wien, Institute for Theoretical Physics, Seminar room DB gelb 10, Wiedner Hauptstraße 8 – 10, B (yellow tower), 10th floor Contact: Univ.Prof. Dr. Joachim Burgdörfer

 The decay of SU(2) Yang-Mills fields on the Schwarzschild black hole with spherically symmetric small energy initial data
 Speaker: Sari Ghanem (Potsdam) Abstract: First, I will present the Yang-Mills equations on arbitrary fixed curved space-times, valued in the Lie algebra associated to any arbitrary Lie group. Thereafter, I will expose recent results with Dietrich Häfner concerning the Yang-Mills fields valued in the Lie algebra su(2) associated to the Lie group SU(2), propagating on the Schwarzschild black hole. We assume that the initial data are spherically symmetric, satisfying a certain Ansatz and have small energy, which excludes the stationary solutions which do not decay. We then prove uniform decay estimates in the entire exterior region of the black hole, including the event horizon, for gauge invariant norms on the Yang-Mills curvature generated from such initial data, including the $L^\infty$ norm of the so-called middle components. This is done by proving in this setting, a Morawetz type estimate that is stronger than the one .. Date: Thu, 30.03.2017 Time: 14:00 Duration: 60 min Location: Arbeitsgruppe Gravitation, Währinger Strasse 17, Raum 218, 2. Stock, 1090 Wien Contact: P.T. Chrusciel

 Kitaev lattice models as a Hopf algebra gauge theory
 Speaker: Prof. Catherine Meusburger (U Erlangen) Abstract: We generalise the notion of a lattice gauge theory with values in a group to Hopf algebra valued lattice gauge theories and show that a Kitaev lattice model for a finite-dimensional semisimple Hopf algebra H is equivalent to a Hopf algebra gauge theory for the Drinfeld double D(H). This shows in particular that Kitaev models are a special case of combinatorial quantisation of Chern-Simons theory introduced by Alekseev, Grosse, Schomerus und Buffenoir and Roche. This can be viewed as an analogue of the relation between Turaev-Viro and Reshetikhin-Turaev TQFTs and explicitly relates Kitaev models to the quantisation of moduli spaces of flat connections on surfaces. Date: Thu, 30.03.2017 Time: 16:00 Duration: 60 min Location: Erwin Schrödinger International Institute, Boltzmanngasse 9, 1090 Wien, Boltzmann lecture hall Contact: secr@esi.ac.at