CPT

Calendar of Physics Talks Vienna

Quantum optics with emitters in waveguides
Speaker:Ignacio Cirac (Max-Planck-Institut für Quantenoptik, München)
Abstract:Recent progress in nano-fabrication and atomic physics has allowed to couple atoms (or other emitters) to structured waveguides. In this talk I will report on:(i) a theoretical framework to describe some of those experiments using both a master equation and a path integral approach; (ii) the existence of many-photon bound states in the presence of one emitter; (iii) some techniques to prepare multi-photon states in the waveguide using strong coupling and collective effects.
Date: Mon, 09.05.2016
Time: 17:30
Location:TU Wien-Freihaus, Hörsaal 5, 2. Stock, grüner Bereich
Contact:Prof. Unterrainer - Prof. Schmiedmayer

Metal-organic coordination networks on metal surfaces: from hierarchical self-assembly to CO2 activation
Speaker:Jan Čechal (CEITEC, Brno University of Technology, Brno/CZ)
Abstract:Systems featuring organic molecules are becoming integral part of wide range of functional devices. The popularity of organic materials can be tracked down to their inherent functional versatility and cost effectivity. The organic building blocks can be designed to bear specific functionality and incorporated into functional architectures. In the talk I will introduce the design principles based on self-assembly of organic molecules for preparation of the extended supramolecular patterns on metal surfaces. The hierarchical assembly will be described on the model system comprising Fe atoms and dicarboxylic acid molecular linkers forming extended network structure further decorated with Ni atoms with the aim to mimic enzymatic systems for CO2 conversion.
Date: Tue, 10.05.2016
Time: 16:00
Location:Technische Universität Wien, Institut für Angewandte Physik, E134 yellow tower „B“, 5th floor, Sem.R. DB gelb 05 B (room number DB05L03) 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Univ.Prof. Dr. Ulrike Diebold

Fun with regularization and renormalization
Speaker:Dominik Stöckinger (TU Dresden)
Abstract:The history of regularization and renormalization is full not only of important breakthroughs and fundamental theorems but also of puzzles and paradoxical, inconsistent, or wrong results. Many issues have been clarified in the past years, leading to interesting conceptual insights into quantum field theory and to results of practical importance. The talk will first focus on variants of dimensional regularization, give a brief overview of the historical development and provide a precise definition of all schemes and their differences. New results regarding the infrared structure of QCD and regarding supersymmetry-preserving regularizations will be explained. Then the talk will focus on the renormalization of gauge theories. The role of Slavnov-Taylor identities as tools will be explained.As an application, the renormalization properties, gauge dependence and beta functions of vacum
Date: Tue, 10.05.2016
Time: 16:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, Y. Wang

Discovery of Sterile Neutrinos at the LHC
Speaker:C.S. KIM (Yonsei Univ., Seoul, Korea)
Date: Wed, 11.05.2016
Time: 11:00
Duration: 60 min
Location:Fakultät für Physik, Ludwig-Boltzmann-Hörsaal, Strudlhofgasse 4, Erdgeschoß
Contact:H. Neufeld, W. Grimus

Estimating source parameters of GW150914: The role of waveform models and numerical relativity simulations
Speaker:Michael Pürrer (MPI Golm)
Abstract:On September 14, 2015, the Laser Interferometer Gravitational-wave Observatory (LIGO) detected a gravitational-wave (GW) transient (GW150914). We characterise the properties of the source and its parameters with Bayesian parameter estimation algorithms using waveform models that describe GWs emitted from binary black holes in general relativity. In addition, we compare these models against a set of numerical relativity (NR) waveforms in the vicinity of GW150914. Simplifications are used in the construction of some waveform models, such as restriction to spins aligned with the orbital angular momentum, no inclusion of higher harmonics in the GW radiation, no modeling of eccentricity and the use of effective parameters to describe spin precession. In contrast, NR waveforms provide us with a high fidelity representation of the "true" waveform modulo small numerical errors. . . . .
Date: Thu, 12.05.2016
Time: 14:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock, 1090 Wien
Contact:H. Rumpf

Antrittsvorlesung Prof. Arno Rauschenbeutel "Glass Fiber Quantum Optics"
Speaker:Prof. Arno Rauschenbeutel (Technische Universität Wien - Atominstitut)
Abstract:Glass fibers play an important role for guiding and controlling light in many areas of everyday life: Owing to their enormous capacity for data transmission, they have become the backbone of the modern information society. Moreover, they have numerous applications in medicine and industry. However, despite the widespread and successful use of glass fiber technology, the design and optimization of novel types of glass fibers for ever more extreme fields of application remains a highly active field of research. In this context, we employ specially designed glass fibers as quantum laboratories. More precisely, we quantum mechanically interface light and matter (atoms, molecules, etc.) near the surface of ultra-thin glass fibers. The strong spatial confinement of the light enhances the light–matter interaction. Such a strong coupling of light and emitters based on glass fibers opens a number of perspectives, including the ultra-high sensitivity detection of molecules and novel types of fiber-optical components, required for quantum communication, quantum cryptography, and for quantum information processing.
Date: Thu, 12.05.2016
Time: 17:00
Location:TU Wien-Freihaus, Hörsaal 5, 2. Stock, grüner Bereich
Contact:Arno Rauschenbeutel

Misner space as a (toy) counterexample to almost anything
Speaker:Juan Margalef ((Universidad Complutense de Madrid, Spain))
Abstract:Abstract: Topology is essential in many branches of mathematics, however in physics it is often taken for granted as it usually plays no crucial role. I will try to show that on some cases topology turns out to be essential in order to understand some pathological behaviors that arise in general relativity. Namely I will talk about the so-called Misner space, which shows extremely pathological behaviors that can be neatly understood through topology. Besides I will introduce the g-boundary, a topological construction introduced by Hawking and Geroch in an attempt to define properly what a singularity is, and I will prove that in the case of the Misner space, one obtains the expected g-boundary
Date: Fri, 13.05.2016
Time: 11:30
Duration: 90 min
Location:Seminarraum 11 (SR 11), Oskar-Morgenstern-Platz 1, 1090 Wien
Contact:M. Bauer, V. Branding (Fak. Math, T.U.), D. Fajman, J. Joudioux (Fak. Phys, U.V.), B. Schoerkhuber (Fak. Math, U.V.)