CPT

Calendar of Physics Talks Vienna

Glueballs and Confinement Physics (1)
Speaker:Steven D. Bass (Stefan-Meyer-Institut für subatomare Physik, ÖAW)
Abstract:QCD confinement physics gives us hadrons and determines their symmetries and interactions. Quark confinement is produced by non-perturbative long-range gluon fields. How do these gluons interact to produce hadrons and can we see gluon physics at work in low energy experiments ? QCD contains the fascinating possibilibilty of new states of matter ("glueballs") built out of gluons and no valence quarks. The search for these new states is a key aim of the PANDA experiment at FAIR. We give an introduction to the physics of confinement and these possible new gluonic states.
Date: Mon, 25.11.2013
Time: 16:00
Duration: 60 min
Location:Seminarraum 2.08, Boltzmanngasse 3, 1090 Wien
Contact:ken.suzuki@oeaw.ac.at

Quantum Information Processing and Metrology Using Few Electron Spins in Solids
Speaker:Amir YACOBI (Harvard University)
Abstract:Quantum computing and information processing use quantum two level systems as their building blocks. Solid-state implementations of quantum bits use, for example, single or few electron spins confined to small spatial dimensions. Harnessing the interaction of such electron spins with their environment offers intriguing possibilities for coherent electrical manipulation and controlled generation of entanglement with promising applications in nanoscale imaging and metrology.
Date: Mon, 25.11.2013
Time: 17:30
Location:TU Wien Freihaus Hörsaal 5, Wiedner Hauptstr. 8, 1040 Wien
Contact:J. Schmiedmayer

Terahertz Radiation-Induced Electric Currents in Dirac Fermions Systems
Speaker:Prof. Sergey D. Ganichev (University of Regensburg)
Abstract:The talk overviews experimental and theoretical studies of photocurrents induced in various Dirac fermions systems by polarized electromagnetic radiation. We consider second order opto-electric phenomena induced by terahertz radiation in graphene and in HgTe/CdHgTe quantum wells. We discuss the phenomenological and microscopic theory of these phenomena and present the state-of-the-art of the experiments aimed to the study of terahertz radiation induced non-linear electron transport. We also show that nonlinear transport opens up new opportunities for probing of Dirac electrons as well as address prospective of future theoretical and experimental studies.
Date: Tue, 26.11.2013
Time: 11:00
Duration: 45 min
Location:TU Freihaus, seminar Room 138C, yellow tower, 9’th floor
Contact:Andrei Pimenov

Hard Particles in Theory, Simulation and Experiment
Speaker:Carina Karner (University of Vienna)
Abstract: In the 1950's, when computational methods were established as new way to study and understand physical phenomena, hard spheres were among the first systems studied. As early as 1957 Alder and Wainwright showed that hard spheres exhibit a first order ordering phase transition. Now, 50 years later, hard spheres and their experimental realizations, colloidal particles with nearly hard interactions are still a very attractive object of research. Nowadays, new real-space imagining techniques enable the experimental study of nucleation of hard colloidal spheres and, by that, testing theoretical findings and numerical results. Besides hard colloidal spheres, experimentalists can now, due to the advent of new fabrication techniques, produce colloidal particles with various shapes or interactions.
Date: Tue, 26.11.2013
Time: 12:30
Duration: 60 min
Location:Vienna University of Technology, Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room E136
Contact:Iva Lovrekovic, Albert Georg Passegger - www.univie.ac.at/lunch-seminar

Asymptotic properties of von Neumann algebras
Speaker:Hiroshi Ando (ESI, Wien) (Mathematische Physik)
Abstract:Abstract: Ultraproducts and Central sequence algebras of II_1 factors have been very useful tools for the structural theory of von Neumann algebras. It is therefore interesting to generalize their construction to non-tracial setting, namely to type III factors. However, due to the lack of the trace, it is not clear how to generalize the definition of ultraproucts/central sequences, and indeed there have been proposed several definitions, which look rather different to each other. In this talk I will explain that all the proposed approaches can be treated in a unified way and this unification provides strutctural results about the ultraproduct of type III factors. In particular, it is shown that the modular flow associated with ultraproduct states is the ultraproduct of the modular flows of states, and the ultraproduct of type III factors may or may not be a factor, depending on the type. This is a joint work with Uffe Haagerup.
Date: Tue, 26.11.2013
Time: 14:15
Location:Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:J. Yngvason

Quantitative Scanning Force Microscopy of the Loops and Curls in DNA
Speaker:Dr. Willem Vanderlinden (KU Leuven, Molecular Imaging and Photonics, Leuven/Belgium)
Abstract:Watson and Crick first proposed their double helix model for dsDNA, they mentioned: “Since the two chains in our model are intertwined, it is essential for them to untwist if they are to separate. Although it is difficult at the moment to see how these processes occur without everything getting tangled, we do not feel that this objection would be insuperable” The entanglement of DNA and Nature’s way of coping with it is the subject of DNA topology. In my talk, I will discuss how the geometry of topologically constrained DNA molecules changes on surface adsorption. This knowledge is crucial for the quantitative assessment of DNA-ligand interactions employing scanning force microscopy (SFM). Furthermore, I will elaborate on the in situ DNA surface dynamics at the solid-liquid interface. Next, results on the DNA structural impact of photo-oxidative Ru(II)-complexes are presented. Ru(II)-c
Date: Tue, 26.11.2013
Time: 16:00
Location:Technische Universität Wien, Institut für Angewandte Physik, Seminarraum 134A, Turm B (gelbe Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Univ.Prof. Dr. Ulrike Diebold

Glueballs and Confinement Physics (2)
Speaker:Steven D. Bass (Stefan-Meyer-Institut für subatomare Physik, ÖAW)
Abstract:QCD confinement physics gives us hadrons and determines their symmetries and interactions. Quark confinement is produced by non-perturbative long-range gluon fields. How do these gluons interact to produce hadrons and can we see gluon physics at work in low energy experiments ? QCD contains the fascinating possibilibilty of new states of matter ("glueballs") built out of gluons and no valence quarks. The search for these new states is a key aim of the PANDA experiment at FAIR. We give an introduction to the physics of confinement and these possible new gluonic states.
Date: Tue, 26.11.2013
Time: 16:00
Duration: 60 min
Location:Seminarraum 2.08, Boltzmanngasse 3, 1090 Wien
Contact:ken.suzuki@oeaw.ac.at

Classical and Quantum Impulsive Scattering
Speaker:Herbert Balasin (TU Wien)
Abstract:im Rahmen des Literaturseminars für Gravitationsphysik
Date: Thu, 28.11.2013
Time: 14:15
Duration: 60 min
Location:Arbeitsgruppe: Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock
Contact:H. Rumpf

The centenary of the birth of Bruno Pontecorvo: “Bruno Pontecorvo and the neutrino”
Speaker:Samoil Bilenky (JINR, Dubna)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Thu, 28.11.2013
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:W. Grimus, H. Neufeld

The core structure of complex networks
Speaker:Bernat Corominas Murtra (Med.Univ.Wien)
Abstract:im Rahmen der gemeinsam veranstalteten Seminare "Komplexe Stochastische Systeme" (Univ.Wien) und "Analyse Komplexer Systeme" (Med.Univ.Wien)
Date: Fri, 29.11.2013
Time: 14:15
Duration: 90 min
Location:Medizinische Universität Wien, Informatikbibliothek Bauteil 88, E 03, Spitalgasse 23
Contact:H. Hüffel, Stefan Thurner

Single photon Kerr effect and deterministic Schrödinger-cat creation in circuit QED
Speaker:Gerhard KIRCHMAIR (Experimental Physics U Innsbruck and Institute of Quantum Optics and Quantum Information (IQOQI) of the ÖAW)
Abstract:The recent development of a 3D architecture for superconducting circuits has dramatically increased the coherence time of qubits and cavities. This allows us to reach the single-photon Kerr regime in circuit QED, where the interaction strength between individual photons in the cavity exceeds the loss rate. Here, using a two-cavity/single-qubit system, we engineer an artificial Kerr medium that enters this regime and allows the observation of new quantum effects. We realize a Gedankenexperiment proposed by Yurke and Stoler, in which the collapse and revival of a coherent state can be observed. During this evolution non-classical superpositions of coherent states, i.e. multi-component Schrödinger-cat states, are formed. We visualize this evolution by measuring the Husimi Q-function and confirm the non-classical properties of these transient states by Wigner tomography. Using a similar two-cavity/single-qubit system we demonstrate a protocol that deterministically maps a qubit state to a superposition of coherent states in a cavity. We extend this method to create multi-component Schrödinger-cat states. These states include the four-component compass state that can be used to realize a quantum memory protected against spontaneous emission.
Date: Fri, 29.11.2013
Time: 15:30
Location:TU Wien Atominstitut, Hörsaal, Stadionallee 2, 1020 Wien
Contact:J. Schmiedmayer

Chiral Transition and Deconfinement in Magnetic QCD
Speaker:Prof. Eduardo Fraga (Universidade do Estado do Rio de Janeiro )
Abstract:We review the influence of a magnetic background on the phase diagram of strong interactions and how the chiral and deconfining transitions can be affected. After some motivation, we summarize results for both transitions obtained in the framework of the linear sigma model coupled to quarks and to the Polyakov loop, and how they compare to other effective model approaches and to lattice QCD. Then we discuss the outcome of the magnetic MIT bag model that yields a behavior for the critical deconfining temperature which is compatible with recent lattice results and magnetic catalysis. The qualitative success of the magnetic MIT bag model hints to Tc being a confinement-driven quantity, and leads us to the discussion of its behavior as predicted within the 't Hooft limit of QCD, which is also in line with the most recent lattice QCD results provided that quarks behave paramagnetically. Finally, we present the first results of a perturbative calculation of the pressure in the limit of very high magnetic fields with a surprising behavior in the chiral limit.
Date: Fri, 29.11.2013
Time: 16:00
Duration: 60 min
Location:Vienna University of Technology, Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room E136
Contact:Andreas Schmitt