Calendar of Physics Talks Vienna

Parity Adiabatic Quantum Computing
Speaker:Wolfgang Lechner (IQOQI Innsbruck)
Abstract:Adiabatic quantum computing is an alternative scheme to gate-based quantum computing with the aim to solve optimization problems efficiently. The working principle of current proposals in this direction is to encode an optimization problem in the interaction matrix of a spin glass Hamiltonian. The ground state of this Hamiltonian is the solution of the problem which is reached by adiabatic switching. The fundamental challenge in building a universal adiabatic quantum computer is the competing requirements of fully programmable all-to-all connectivity and the quasi locality of the interactions between physical qubits. In this talk, I will present a programmable and scalable architecture with full connectivity, which can be implemented with local interactions only. The input is encoded in local fields acting on an extended set of physical qubits. The output is encoded redundantly in ...
Date: Mon, 30.11.2015
Time: 17:30
Duration: 60 min
Location:Ernst-Mach Hörsaal, 2. Stck.,Strudlhofgasse 4, 1090 Wien
Contact:www.coqus.at / Christina Becker

Sphingomyelin specific triggering of in-membrane oligomerization of β-amyloid and the inhibitory effect of monosialoganglioside GM1
Speaker:Prof. Dr. Martin Hof (Department of Biophysical Chemistry, J. Heyrovsky Insitute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague/CZ)
Abstract:Oligomers of the β-amyloid (Aβ) peptide are thought to be implicated in Alzheimer’s disease. The plasma membrane of neurons may mediate the oligomerization of Aβ present in brain. Using the single-molecule sensitivity of fluorescence, we address the oligomerization of Aβ monomers on lipid bilayers containing essential components of the neuronal plasma membrane. We find that Sphingomyelin triggers the oligomerization of Aβ and that physiological levels of GM1, organized in nanodomains, do not seed oligomerization. Moreover, GM1 prevents oligomerization of Aβ counteracting the effect of Sphingomyelin. We discuss the molecular explanation for the above observations using all-atom molecular dynamics simulations. Our results establish a preventive role of GM1 in the oligomerization of Aβ suggesting that decreasing levels of GM1 in brain, e.g. due to aging, could lead to reduced protection fro
Date: Tue, 01.12.2015
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

Proton lifetime in minimal gauge unifications
Speaker:Michal Malinsky (Charles University, Prague)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Tue, 01.12.2015
Time: 16:15
Duration: 60 min
Location:Fakultät für Physik, Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:W. Grimusl, H. Neufeld

Marine Primary and Secondary Aerosol emissions related to seawater biogeochemistry from a mesocosm and laboratory study
Speaker:Dr. Barbara D'Anna
Date: Tue, 01.12.2015
Time: 17:30
Duration: 60 min
Location:Lise-Meitner Hörsaal (ehemal. Großer Hörsaal der Experimentalphysik), Universität Wien
1090 Wien, Strudlhofgasse 4 / Boltzmanngasse 5

The many faces of the constraints in general relativity
Speaker:Istvan Racz (Budapest)
Abstract:In this talk the constraint equations for smooth spaces satisfying Einstein's equations will be considered. It is shown that, regardless whether the primary space is Riemannian or Lorentzian, the constraints can always be put into the form of an evolutionary system comprised either by a first order symmetric hyperbolic system and a parabolic equation or, alternatively, by a symmetrizable hyperbolic system subsided by an algebraic relation. The (local) existence and uniqueness of solutions to these evolutionary systems is also shown verifying thereby that the proposed evolutionary approach provides a viable alternative to the apparently unique conformal method.
Date: Thu, 03.12.2015
Time: 14:00
Duration: 60 min
Location:Arbeitsgruppe Gravitation, Währinger Strasse 17, Seminarraum, 5. Stock, 1090 Wien
Contact:P.T. Chrusciel

Low-Lying Excitations in the Orbitally Active A-Site Spinels FeSc2S4 , FeCr2O4 and FeCr2S4
Speaker:Joachim Deisenhofer (Institute of Physics, University of Augsburg, Germany)
Abstract:The spinel systems FeSc2S4, FeCr2O4, and FeCr2S4 show cubic symmetry at room temperature, but they reveal very different magnetic ground states at low temperatures. FeSc2S4 does not reveal any structural transition below room temperature, but forms a spin-orbital liquid state at lowest temperatures. In FeCr2S4 a long-range ferromagnetic order is followed by an incommensurate magnetic structure. Finally, a multiferroic state with orbital order is reached. Similar magnetic structures occur in FeCr2O4, but a tetragonal distortion precedes magnetic ordering and indicates a stronger Jahn-Teller coupling than in FeCr2S4. These different states are tracked and discussed via optical excitations using THz- and FIR-spectroscopy.
Date: Fri, 04.12.2015
Time: 14:00
Duration: 45 min
Location:Seminar Room CBEG02 (387, Photonics); Gußhausstraße 27
Contact:Andrei Pimenov