Calendar of Physics Talks Vienna

The physics questions associated with experiments at the n_TOF facility at CERN
Speaker:Dr. Alberto Mengoni (E141/2)
Date: Mon, 24.11.2008
Time: 16:00
Location:Sem. 134A, Freihaus, Turm B, 5. OG

What`s up Spins? Simulating the Quantum Magnet
Speaker:Dr. Tobias Schätz (Max Planck Institute for Quantum Optics, Garching/Germany)
Abstract:We can not translate quantum behaviour arising with superposition states or entanglement efficiently into the classical language of conventional computers. A universal quantum computer could describe and help to understand complex quantum systems. But it is envisioned to become functional only within the next decade(s). A shortcut was proposed by Richard Feynman already in 1982, via simulating the quantum behaviour of interest in another quantum system, where all relevant parameters and interactions can be controlled and observables of interest detected sufficiently well. For experts in the field of quantum information/computation we describe the demonstration of an analog quantum simulator based on trapped ions proposed in 2003 (feasibility study on two spins). We proof in principle that a rich spectrum of problems, intractable on classical computers, can be addressed. For general recognition, we explain the complete mode of operation of a quantum simulator on the basis of a simple model case. We revile the difficulties in describing a quantum system classically for the case of a quantum magnet, where we introduce and explain the role of superposition states, entanglement and tunneling (quantum fluctuations) by means of our experimental data and emphasize the similarities and discrepancies between quantum simulations and quantum computation.
Date: Mon, 24.11.2008
Time: 17:30
Duration: 60 min
Location:TU Wien, Freihausgebäude HS 5, Wiedner Hauptstraße 8, Turm A, grüner Bereich, 2. OG, A 1040 Wien
Contact:Prof. Jörg Schmiedmayer

Vienna Theory Lunch Club - Semileptonic Kaon decays in Chiral perturbation theory
Speaker:Andreas Kastner (Uni Wien)
Abstract:Due to quark confinement QCD, the quantum field theory of strong interactions, becomes non-perturbative at low energy. In order to obtain predictions for strong processes in the energy region of confinement, one can use a so called effective field theory. Chiral perturbation theory (ChPT), the low-energy limit of the standard model, only makes use of the symmetries of the QCD Lagrangian and does not invoke the dynamics of quarks and gluons. We want to show the basic properties and problems of effective field theories by discussing the predictions of the standard model for specific kaon decays, the K_l3 decays, in ChPT, including isospin violating effects of strong and electromagnetic origin.
Overview Vienna Theory Lunch Club
Date: Tue, 25.11.2008
Time: 12:30
Duration: 60 min
Location:University of Vienna, Boltzmanngasse 5, 5th Floor, Large Seminar Room
Contact:Max Attems, Daniel Grumiller, Beatrix Hiesmayr

Stability of self-similar solutions of semilinear wave equations
Speaker:Dr. Roland Donninger (Univ. Wien) (Fakultät für Physik)
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Tue, 25.11.2008
Time: 14:15
Duration: 60 min
Location:Großer Seminarraum, Boltzmanngasse 5, 5. Stock
Contact:J. Yngvason

Scattering mechanism of electrons interacting with surfaces in specular reflection geometry
Speaker:Dr. Alessandro Ruocco (Dipartimento di Fisica, Universitá Roma Tre, Rom/Italy)
Abstract:In this seminar I will present our study concerning the scattering mechanism of the electron-energy-loss process in specular reflection geometry highlighting the presence of an elastic collision that always accompanies the inelastic one. It implies that two independent channels contribute to the inelastic cross section depending on whether the inelastic event precedes or follows the elastic one. Our results indicate that neither one of the channels is favored by propensity rules. Nevertheless, suitable experimental conditions permit to enhance contribution to the cross section of one channel with respect to the other. The possibility to single out the contribution of a given channel allows to determine without ambiguity the momentum exchanged in the inelastic collision. This is of fundamental relevance for several electron impact spectroscopies, such as electron-energy-loss spectroscopy and (e,2e), in specular reflection geometry. These results are derived from measuring the current of elastically and inelastically specularly reflected electrons as a function of the primary electron beam kinetic energy (IV curve) on different clean surfaces (HOPG, Ni(110), Al(100). The incident beam energy was varied between 100 and 500 eV and the range of losses investigated was 6–35 eV. I will also discuss the application of the these results to the interpretation of two electron scattering experiments: the determination of the orientation of a molecular overlayer grown on a metallic substrate (copper-phthalocyanine on Al(100)) and the line shape of emitted electron from aluminum surface in the plasmon decay coincidence measurements.
Date: Tue, 25.11.2008
Time: 16:00
Location:Technische Universität Wien, Institut für Allgemeine Physik, Seminarraum 134A, Turm B (gelbe Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Ao.Univ.Prof. Dr. Wolfgang Werner

Low-scale Gravity Black Holes at LHC
Speaker:Enikö Regös (CERN) (Fakultät für Physik)
Abstract:im Rahmen des Literaturseminars
Date: Thu, 27.11.2008
Time: 13:30
Duration: 60 min
Location:Seminarraum B, Währinger Straße 17, 1. Stock
Contact:H. Rumpf

Vienna Central European Seminar on Particle Physics and Quantum Field Theory
Speaker:Konstantinos Anagnostopoulos (Athens), Michael Creutz (Brookhaven), Philippe de Forcrand (Zurich), Christof Gattringer (Graz), Nigel Glover (Durham), Dieter Kranzlmüller (Munich), Thomas Lippert (Juelich), Owe Philipsen (Muenster), Michael Seymour (CERN), Jos Vermaseren (Amsterdam)
Abstract:This year, Highlights in Computational Quantum Field Theory has been chosen as subject. The present status of Monte Carlo event generation for collider experiments and the GRID technology are presented. In perturbative quantum field theory automation of loop and precision calculations are covered, at the nonperturbative level advances in lattice QCD as well as simulations of M-theory, supergravity and black holes.
5th Vienna Central European Seminar, 2008
Date: Fri, 28.11.2008
Time: 09:00
Location:Großer Hörsaal Materialphysik, Strudlhofgasse 4, 3rd floor, 1090 Vienna
Contact:Helmuth Hüffel

Making the Molecular Movie: The Quest for the Structure-Function Correlation in Biology
Speaker:Dr. R.J. Dwayne Miller (Institute for Optical Sciences, University of Toronto, Canada)
Date: Fri, 28.11.2008
Time: 15:00
Duration: 60 min
Location:Kleiner Hörsaal der Experimentalphysik,1090 Wien, Strudlhofgasse 4/Boltzmanngasse 5, 2. Stock
Contact:Heike Höller, SFB ADLIS Sekretariat, Tel: 58801 13625

State selective micro-wave potentials: Towards a controlled phasegate on an atom chip
Speaker:Pascal BOEHI (LMU München)
Date: Fri, 28.11.2008
Time: 15:15
Location:Seminarraum Atominstitut, Stadionallee 2, 1020 Wien
Contact:Jörg Schmiedmayer