CPT

Calendar of Physics Talks Vienna

Optomechanic
Speaker:Dr. Florian Marquart (LMU Munich, Germany)
Abstract:In this talk I will review recent progress in the physics of the interaction between radiation and mechanical motion. The paradigmatic system in this field of 'optomechanics' consists of an optical cavity with a movable mirror attached to a cantilever. I will discuss how the coupled dynamics of the light field inside the cavity and the cantilever motion gives rise to a series of interesting effects. On the level of classical dynamics, I will present the theory of nonlinear oscillations and the corresponding attractor diagram. Furthermore, it is possible to cool the cantilever by irradiating the cavity with a red-detuned laser beam. I will present the quantum theory of optomechanical cooling and discuss the prospects for reaching the ground state of the cantilever's center-of-mass motion. Among the interesting opportunities that open up in the quantum regime, I discuss the quantum nonlinear dynamics of an optomechanical system and the possibility of detecting quantum jumps between states of a macroscopic mechanical oscillator.
Date: Mon, 17.11.2008
Time: 17:30
Duration: 60 min
Location:TU Wien, Elektrot.Institutsg., EI 8 Pötzl Hörsaal, Gußhausstr. 25-29, Stiege 1, EG, 1040 Wien
Contact:Prof. Jörg Schmiedmayer/ Dr. Johannes Majer

Vienna Theory Lunch Club - Geometric entanglement witnesses
Speaker:Philipp Krammer (Uni Wien)
Abstract:A challenge in quantum information theory is the detection of entangled states on a finite dimensional Hilbert space. Useful tools for this purpose are entanglement witnesses; they provide a geometrically intuitive method to detect entanglement. I will explain the concept of entanglement witnesses and how to combine it with the notion of Bloch decompositions. Geometric entanglement witnesses are a simple example for a geometrical construction of witnesses. I will show how to use "shifts" of such witnesses in order to detect entanglement and to find the set of separable states for a convex subset of states.
Overview Vienna Theory Lunch Club
Date: Tue, 18.11.2008
Time: 12:30
Duration: 60 min
Location: TU Vienna, Inst. f. Theoretical Physics, Freihaus, Wiedner Hauptstr. 8-10, 10. OG, SEM136
Contact:Max Attems, Daniel Grumiller, Beatrix Hiesmayr

marik@iap.tuwien.ac.atWires and switches: Model systems for molecular nanotechnology studied by STM
Speaker:Dr. Leonhard Grill (Freie Universität Berlin, Institut für Experimentalphysik, Berlin/D)
Abstract:The idea of “molecular nanotechnology” is based on the capabilities of synthetic chemistry to functionalize molecules and to use them as electronic devices, sensors or complex “nano-machines”. The scanning tunneling microscope (STM) is one of the most important instruments for the investigation of functionalized molecules, because it can image single molecules with submolecular resolution and is also capable to manipulate them by chemical/electrostatic forces or inelastic tunneling processes. In this talk several functional molecules, which can be considered as model systems, will be discussed. This concerns on the one hand the controlled growth of molecular wires that are covalently bound to each other. Such bonds are highly stable and allow charge transport between the molecules. By choosing suitable chemical structures of the initial molecular building blocks, the nano-architectures of the formed structures can be precisely controlled. Moreover, molecular switches on surfaces will be presented. Our results show that azobenzene-based molecules, adsorbed on a metal surface, can be reversibly switched between trans and cis isomers by different processes. It turns out that the chemical side groups of the molecules play a fundamental role for their switching capabilities
Date: Tue, 18.11.2008
Time: 15:00
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. Peter Varga

Risiko-Controlling in Banken: Theorie und Praxis
Speaker:Dr. Christoph Schwärzler (Stv. CRO, Österreichische Kontrollbank AG)
Abstract:Vor dem Hintergrund der aktuellen Finanzkrise wird in dem Seminar eine Übersicht über Methoden und Modelle des modernen Bankrisikomanagements präsentiert. Durch Basel II wurde die Bewertung bankspezifischer Risiken auf eine ganz neue, stärker nach quantitativen Kriterien ausgerichtete, Basis gehoben. Dennoch suggeriert die aktuelle Entwicklung ein Versagen der Kontrollmechanismen. Einige Ursachen und mögliche Auswirkungen werden praxisnah illustriert.
Date: Tue, 18.11.2008
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. Herbert Störi

Isosinglet quarks and rare K and B decays
Speaker:Branimir Radovcic (Univ.Wien) (Fakultät für Physik)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Tue, 18.11.2008
Time: 16:15
Duration: 60 min
Location:Großer Seminarraum, Boltzmanngasse 5, 5. Stock
Contact:W. Grimus, H. Neufeld

Kochen-Specker theorem and neutron measurements
Speaker:Adán CABELLO (University of Sevilla)
Date: Fri, 21.11.2008
Time: 14:15
Location:Seminarraum Atominstitut, Stadionallee 2, 1020 Wien
Contact:Jörg Schmiedmayer

Contextuality and Kochen-Specker
Speaker:Brian LACOUR (University of Texas-Austin)
Date: Fri, 21.11.2008
Time: 14:15
Location:Seminarraum Atominstitut, Stadionallee 2, 1020 Wien
Contact:Jörg Schmiedmayer