Calendar of Physics Talks Vienna

Vienna Theory Lunch Club - Yoctosecond light flashes from heavy ion collisions
Speaker:Andreas Ipp (TU Vienna)
Abstract:Collisions of heavy ions in particle accelerators like RHIC and soon LHC can produce the quark-gluon plasma, a new state of matter at ultra-hot temperatures, for the time of a few yoctoseconds. Besides many particles that are produced in such collisions, also high-energy photons are emitted from the plasma. We focus on photons produced in the plasma through Compton scattering of gluons and quark-antiquark annihilation. Looking at the time-evolution of the photon emission for the anisotropically expanding plasma, we find under certain conditions double pulses at the yoctosecond time scale. Such double pulses may be utilized in the future for novel pump-probe experiments at nuclear time scales.
Overview Lunch Seminar
Date: Tue, 10.11.2009
Time: 12:30
Duration: 60 min
Location:University of Vienna, Boltzmanngasse 5, 5th Floor, Large Seminar Room
Contact:Maximilian Attems, David Burke, Marcus Huber, Theo Adaktylos

Der Übergang zum Riesen-Vortex in schnell rotierende Bose-Einstein Kondensation
Speaker:Jakob Yngvason (Univ. Wien) (Fakultät für Physik)
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Tue, 10.11.2009
Time: 14:30
Duration: 60 min
Location:Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:Jakob Yngvason

Ultrashort Laser Matter-Interaction
Speaker:M.Phil. Shazia Bashir (Technische Universität Wien, Institut für Angewandte Physik)
Abstract:Recent advances in high-intensity femtosecond laser pulses have made it possible to induce various nanostructures inside a variety of materials. Phenomena of nanohillock-like-defect-formation, explosions, bumps, nanopores and nanogratings like features on surfaces of CaF2, CR-39 (insulators), Si (semiconductors), Al and Au (metals), by ultra short laser irradiation have been investigated using an Atomic Force Microscope (AFM). The targets were irradiated to Ti:sapphire 25-fs laser pulses with a central wavelength at 800 nm for different fluences (0.06 Jcm-2 to 3.6 Jcm2) in air as well as under UHV. By combining studies of the surface topography and the emission characteristics of particles during interaction of ultra-short-laser radiation with surfaces in particular during laser ablation, three different types of general processes (sub 100 fs electronic processes like Coulomb explosion (CE) or field ion emission by Surface Optical Rectification (SOR), processes related to electronic plasma (FEP) formation (typically a few hundred fs time scale) and thermal ablation (TA)) could be identified to explain ultrashort- laser ablation of matter at laser intensities around the ablation threshold. In particular, the identification of the unique appearance of individual, localized nano-hillocks, typically a few nm in height and with a diameter below typically 50 nm, can be regarded as characteristic for a strong localized potential energy deposition to the electronic system resulting in CE or SOR. Surface topographical features of irradiated materials are well correlated with the structural changes explored by Raman spectroscopy and nonlinear absorption properties ascertained by Z-scan technique.
Date: Tue, 10.11.2009
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 Husinsky

Entanglement in non-inertial frames and curved spacetime
Speaker:Dr. Ivette Fuentes-Schuller (University of Nottinham)
Abstract:The insight that the world is fundamentally quantum mechanical inspired the development of quantum information theory. However, the world is not only quantum but also relativistic, and indeed many implementations of quantum information tasks involve truly relativistic systems. In this talk I consider relativistic effects on entanglement in flat and curved spacetimes. I will emphasize the qualitative differences to a non-relativistic treatment, and demonstrate that a thorough understanding of quantum information theory requires taking relativity into account. The exploitation of such relativistic effects will likely play an increasing role in the future development of quantum information theory. The relevance of these results extends beyond pure quantum information theory, and applications to foundational questions in cosmology and black hole physics will be presented.
Date: Thu, 12.11.2009
Time: 16:00
Duration: 90 min
Location:IQOQI, Seminarraum 2.08, Boltzmanngasse 3, 2nd floor, 1090 Wien
Contact:Prof. Reinhold Bertlmann