CPT

Calendar of Physics Talks Vienna

Multiferroics
Speaker:Alois LOIDL (Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg)
Abstract:In today’s electronics ferroelectrics and ferromagnets play a key role and are used in a wide range of applications. The quest for multiferroic materials, where these two phenomena are intimately coupled is of great fundamental and technological importance. The most considered multiferroics are those who combine ferroelectricity and ferromagnetism and in addition reveal strong magnetoelectric coupling, which allows the control of magnetization by electric fields and the control of polarization by magnetic fields. This talk will provide a broad introduction into the basics of multiferroics, of magnetoelectric coupling and of possible applications. Specifically I will focus on different routes to induce multiferroic order in single phase materials, like multiferroicity induced by charge order or spin-driven ferroelectricity. In the latter case the switching of the ferroelectric polarization by external magnetic fields can be experimentally demonstrated. In addition, I will discuss the observation of electromagnons in multiferroics constituting a new fundamental class of excitations.
Date: Mon, 11.06.2012
Time: 17:30
Location:TU Wien Freihaus, Hörsaal 5, 2. Stock (grüner Bereich), Wiedner Hauptstr. 8, 1040 Wien
Contact:H.-J. Schmiedmayer

Störungstheoretische Konstruktion der wechselwirkenden Feldalgebra
Speaker:Matthias Plaschke (Univ.Wien)
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Tue, 12.06.2012
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:J. Yngvason

Surface Science of Oxide Semiconductors
Speaker:Prof. C.F. McConville (Department of Physics, University of Warwick, Coventry CV4 7AL UK)
Abstract:Oxide semiconductors have become of great interest lately with enormous opportunities for new uses that will potentially improve existing materials and device applications. The fact that some of these materials, such indium tin oxide (ITO), have been around for some time and, in a relatively low quality form have seen significant industrial use as transparent conductors, has perhaps contributed to the belated recognition of the possibilities as semiconductors in their own right. Here, the surface and bulk electronic properties of epitaxially grown high-quality oxide semiconductors (In2O3, CdO, and ZnO) will be discussed and the effects of modifying these surfaces by adsorption and surface treatment. Optical, electronic and structural properties of these semiconducting oxide films will be presented. The valence band density of states and the surface electronic properties of these oxide semiconductors have been studied using high-resolution angle-resolve photoemission spectroscopy (ARPES) and compared with theoretical band structure calculations. A common property of these oxide semiconductors is found to be the presence of a surface electron accumulation layer, in marked contrast to the electron depletion generally observed at the surfaces of conventional semiconductor materials. Additionally, hydrogen is found to be a donor and any native defects have a propensity to be donors in already n-type material. The origins of this phenomenon will be discussed in terms of the band structure and intrinsic properties of these materials.
Date: Tue, 12.06.2012
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

Kaon physics at CERN: recent results and prospects
Speaker:Brigitte Bloch-Devaux (Univ.Turin)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Thu, 14.06.2012
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:H. Neufeld

Topological censorship from the initial data point of view
Speaker:Gregory Galloway (Miami)
Abstract:im Rahmen des Literaturseminars
Date: Thu, 14.06.2012
Time: 14:15
Duration: 60 min
Location:Arbeitsgruppe: Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock
Contact:R. Beig

Status of the NICA Project at JINR
Speaker:Prof. Alexander Sorin (Joint Institute for Nuclear Research (Dubna))
Abstract:The NICA (Nuclotron-based Ion Collider fAcility) project is now under realization phase at JINR (Dubna). The main goal of the project is an experimental study of hot and dense strongly interacting matter in heavy ion collisions at centre-of-mass energies √s_NN = 4 - 11 GeV (NN-equivalent) and average luminosity of 10E27 cm-2 s-1 for Au(79+) in the collider mode (NICA collider). In parallel, fixed target experiments at the upgraded JINR superconducting synchrotron Nuclotron are carried out with extracted beams of various nuclei species up to Au(79+) with maximum momenta 13 GeV/c (for protons). The project also foresees a study of spin physics with extracted and colliding beams of polarized deuterons and protons at the energies up to √s = 26 GeV (for protons). The proposed program allows to search for possible signs of the mixed phase and critical endpoint as well as to shed light on the problem of nucleon spin structure. General design and construction status, physical program of the NICA complex will be presented.
Date: Thu, 14.06.2012
Time: 16:00
Duration: 60 min
Location:Seminar room E136, yellow area, 10th floor, TU Wien (Wiedner Hauptstr. 8-10)
Contact:Andreas Schmitt

Event-by-event analyzis of the properties of the initial conditions in heavy ion collisions
Speaker:Philipe Mota (Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil)
Abstract:The qualitative success of the hydrodynamic approach in describing the collective observables in heavy ion collisions -- such as elliptic flow -- has placed it as an important phenomenological tool to connect the experimental results with theoretical models based on QCD. However the presently available observables are not sensible enough to the space-time evolution of the fluid in order to falsify these models. In this talk I will discuss how one can search for new observables by systematically analyzing the event-by-event hydrodynamic response to the granularity of the initial condition. For this purpose we propose a parametrization of the initial condition based on the Glasma picture. Each collision event is described as a set of overlapping longitudinal tubes where the total energy content and the width of each tube are taken as the parameters. We expect that the comparison of our results with experimental data will provide a better understanding of the space-time evolution of the strongly interacting matter created in heavy ion collisions.
Date: Fri, 15.06.2012
Time: 13:00
Duration: 60 min
Location:Seminar room E136, yellow area, 10th floor, TU Wien (Wiedner Hauptstr. 8-10)
Contact:Denis Parganlija

Quantum (Gauge) Field Theory on Bipartite Lattices
Speaker:Helmuth Hüffel (Univ.Wien)
Abstract:im Rahmen der gemeinsam veranstalteten Seminare "Komplexe Stochastische Systeme" (Univ.Wien) und "Analyse Komplexer Systeme" (Med.Univ.Wien)
Date: Fri, 15.06.2012
Time: 14:15
Duration: 90 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:H. Hüffel, Stefan Thurner

Black hole analogs - direct and indirect
Speaker:Daniel GRUMILLER (Institut für Theoretische Physik, TU Wien)
Abstract:Black holes for a long time were a theoretical prediction of general relativity with no experimental support. Astrophysical observations in the past decades have provided overwhelming evidence in favor of black holes, so that there is no reasonable doubt about their existence. However, certain features of black hole physics still remain in the realm of pure theoretical prediction/speculation, including the famous Hawking effect and other quantum aspects of evaporating black holes. It is possible to test some of these predictions using black hole analogs. I describe how these analog models can emerge from rather simple hydrodynamics. Finally, I introduce an indirect way to generate black hole analogs, namely by virtue of the gauge/gravity correspondence.
Date: Fri, 15.06.2012
Time: 15:30
Location:TU Wien Atominstitut, Hörsaal, Stadionallee 2, 1020 Wien
Contact:H.-J. Schmiedmayer