Calendar of Physics Talks Vienna

Picosecond photocurrents and terahertz generation in nanoscale circuits
Speaker:Alexander W. Holleitner (Walter Schottky Institute and Physik-Department, TUM)
Abstract:The time-resolved dynamics of photogenerated charge carriers in nanoscale systems are typically detected by optical methods such as the transient absorption technique and the time-resolved photoluminescence spectroscopy. Many questions remain concerning the separation and transport of photogenerated charge carriers to source and drain leads, when the nanosystems shall be functional modules in (opto-)electronic circuits. Typical propagation times of ballistic photogenerated charge carriers in nanoscale circuits are in the ps-regime. Conventional electronic measurements cannot resolve such ultrafast dynamics because available electronic equipment cannot produce trigger signals and detect transients faster than tens of picoseconds. Furthermore, nanosystems typically exhibit a high impedance of several kilo-ohms, and ultrafast charge-carrier dynamics are therefore obscured by the response ti
Date: Mon, 18.06.2012
Time: 17:30
Duration: 60 min
Location:TU Wien, Schütte-Lihotzky Hörsaal, HS 7, Karlsplatz 13, 1040 Wien
Contact:Dr. Christiane Losert / Univ. of Vienna

Yang-Mills Theory at Non-Vanishing Temperature
Speaker:Leonard Fister (Universität Heidelberg)
Abstract:We study the temperature dependence of correlators in Yang-Mills theory. For this purpose we utilise a purely thermal renormalisation group flow equation, and obtain the full thermal propagators. Interestingly, the electric screening mass is sensitive to the confinement-deconfinement phase transition. We also compute thermodynamic quantities such as the pressure.
Date: Tue, 19.06.2012
Time: 12:30
Duration: 60 min
Location:TU Wien ( Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room E136 )
Contact:Vienna Theory Lunch Seminar (http://www.univie.ac.at/lunch-seminar/)

Die Renormierungsgruppe in der störungstheoretischen AQFT
Speaker:Christian Köhler
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Tue, 19.06.2012
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:J. Yngvason

On the emission of secondary electrons from solids - Coincidence experiments and dielectric formalism
Speaker:Dipl.-Ing. Francesc Salvat-Pujol (Technische Universität Wien, Institut für Angewandte Physik)
Abstract:The emission of secondary electrons (SE) from solid surfaces is a physical phenomenon which has been known for over a hundred years. It plays a relevant role in a number of applications, for instance in particle-detector technology (channeltrons, microchannel plates, photomultiplier tubes, etc.). In charged-particle accelerators, the presence of a cloud of SE emitted from the walls of the accelerator affects the stability of the particle beam. Similarly, SE emission critically affects the charge balance in electronic devices such as plasma displays. In spite of its widespread use, the mechanisms responsible for SE emission are far from being understood on a detailed and quantitative level: recent independent measurements of the SE yield from aluminum under electron bombardment exhibit discrepancies of as much as a factor of seven. In this seminar talk I will present the outcome of a series of measurements of SE emission in coincidence with selected energy losses of backscattered electrons from several materials. The experimental data give insight into the mechanisms responsible for SE emission in an unprecedented detail. The interpretation of the measured data is supported by Monte Carlo simulations of electron transport. A brief overview of the semiclassic dielectric formalism used to describe energy losses (both in the bulk of the medium and in the surface region) will be given in addition, paying special attention to highlight surface excitations and the role they play in SE emission.
Date: Tue, 19.06.2012
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:Ao.Univ.Prof. Dr. Wolfgang Werner

Exploring the Energy Frontier- Latest Results from the LHC
Speaker:Claudia-Elisabeth Wulz (Institut für Hochenergiephysik)
Abstract:The excellent performance of the Large Hadron Collider has so far led to more than 10 inverse femtobarn of proton-proton collision events delivered to each of the general-purpose experiments ATLAS and CMS. In 2012 the centre-of-mass energy was raised from 7 to 8 TeV, currently the highest energy ever achieved by an accelerator, which will enable to explore new frontiers. A large number of topics is being studied, ranging from standard model physics to exotica. Interesting results in the field of the standard model will be presented, including the status of the search for the Higgs boson in several decay channels.
Date: Wed, 20.06.2012
Time: 17:00
Duration: 60 min
Location:Institut für Hochenergiephysik, 1050 Wien, Nikolsdorfer Gasse 18, Bibliothek, 1. Stock
Contact:Ken Suzuki, 01 4277 29725

General relativistic effects in quantum interference
Speaker:Magdalena Zych (Vienna)
Abstract:im Rahmen des Literaturseminars
Date: Thu, 21.06.2012
Time: 14:15
Duration: 60 min
Location:Arbeitsgruppe: Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock
Contact:R. Beig

Computational uncertainties in public BR (B → Xs γ) codes
Speaker:Sebastian Frank (HEPHY, Wien)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Thu, 21.06.2012
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, H. Neufeld

Citizen Science
Speaker:Christos Tsiapalis (Med.Univ.Wien)
Abstract:im Rahmen der gemeinsam veranstalteten Seminare
Date: Fri, 22.06.2012
Time: 14:15
Duration: 90 min
Location:Medizinische Universität Wien, Informatikbibliothek Bauteil 88, E 03, Spitalgasse 23
Contact:H. Hüffel, Stefan Thurner

Results on the Chameleon fields
Speaker:Guillaume PIGNOL (Lab. de Physique Subatomique & Cosmologie, Grenoble)
Date: Fri, 22.06.2012
Time: 15:30
Location:TU Wien Atominstitut, Hörsaal, Stadionallee 2, 1020 Wien
Contact:H. Abele