CPT

Calendar of Physics Talks Vienna

STM study of oxygen adsorption at defect sites at the TiO2 anatase (101) surface
Speaker:Martin Fidler (Technische Universität Wien, Institut für Angewandte Physik)
Abstract:The adsorption of oxygen at low temperatures (105 K) was investigated by LT-STM on the TiO2 anatase (101) surface. Tersoff-Haman-STM simulations are in good agreement with our experimental data. Surface oxygen vacancy defects were generated by bombarding the surface with 500 eV electrons at 105 K and analyzed with STM. The interaction between vacancies and oxygen shows interesting results.
Date: Mon, 07.11.2011
Time: 14:00
Location:Technische Universität Wien, Institut für Angewandte Physik, Sitzungszimmer, Turm C (rote Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Univ.Prof. Dr. Ulrike Diebold

Bulk characterization and surface properties of In2O3(001) single crystals
Speaker:Daniel Hagleitner (Technische Universität Wien, Institut für Angewandte Physik)
Abstract:Indium oxide, In2O3 is an important semiconductor with a wide range of technical applications including Organic Light Emitting Diodes, Organic Photovoltaic Cells, gas sensing, and transparent infrared reflectors. The present diploma thesis comprises a comprehensive bulk and surface investigation of high-quality In2O3(001) single crystals. The transparent-yellow, cube-shaped single crystals were grown by the flux method. The results of the applied techniques – including four-point-probe measurements, SIMS, XRD, STM, scanning tunneling spectroscopy and photoelectron spectroscopy – will be presented and discussed.
Date: Mon, 07.11.2011
Time: 14:00
Location:Technische Universität Wien, Institut für Angewandte Physik, Sitzungszimmer, Turm C (rote Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Univ.Prof. Dr. Ulrike Diebold

Quantum interferometric visibility as a witness of general relativistic proper time
Speaker:Magdalena Zych (Uni Wien)
Abstract: Current attempts to probe general relativistic effects in quantum mechanics focus on precision measurements of phase shifts in matter-wave interferometry. Yet, phase shifts can always be explained as arising due to an Aharonov-Bohm effect, where a particle in a flat space-time is subject to an effective potential. Here we propose a novel quantum effect that cannot be explained without the general relativistic notion of proper time. We consider interference of a "clock" - a particle with evolving internal degrees of freedom - that will not only display a phase shift, but also reduce the visibility of the interference pattern. According to general relativity proper time flows at different rates in different regions of space-time. Therefore, due to quantum complementarity the visibility will drop to the extent to which the path information becomes available from reading out the proper time from the "clock". Such a gravitationally induced decoherence would provide the first test of a genuine general relativistic notion of proper time in quantum mechanics.
Date: Tue, 08.11.2011
Time: 12:30
Duration: 60 min
Location:Uni Wien ( Boltzmanngasse 5, 5th floor, Schrödinger HS / large seminar room )
Contact:Sabine Ertl

String- and brane-localized causal fields in a strongly nonlocal model (by Buchholz and Summers)
Speaker:Sabina Alazzawi (Univ.Wien)
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Tue, 08.11.2011
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock, 1090 Wien
Contact:J. Yngvason

Relating the N=4 SYM low-energy effective action with D3 brane on AdS_5 x S5 background
Speaker:Igor Samsonov (INFN, Padua)
Abstract:According to the AdS/CFT correspondence, the action for a D3 brane moving in curved AdS_5 x S5 background of IIB theory should coincide with the quantum low-energy effective action in the N=4 SYM theory. This correspondence can be checked explicitly for several leading terms in these actions, in particular, for F4/X4, F6/X8 and for the Wess-Zumino terms. Here F is the Maxwell field strength and X is the R-invariant combination of six scalar fields in the N=4 SYM theory. We discuss some superspace methods to study this matching.
Date: Tue, 08.11.2011
Time: 16:00
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock, 1090 Wien
Contact:Harold Steinacker

X-ray laser spectroscopy of plasmas: reproducing the surroundings of black-holes in the laboratory
Speaker:Priv.-Doz. Dr. José R. Crespo López-Urrutia (Max-Planck-Institut für Kernphysik, Heidelberg/D)
Abstract:Laser spectroscopy in the soft X-ray region has become possible through the combination of free-electron lasers and trapped highly charged ions (HCI). Their electronic structure offers narrow bound-to-bound transitions in the X-ray domain, which can be resonantly excited with photons from fourth-generation sources. Furthermore, photoionization of HCI, widely found in astrophysical environments, can now be replicated in the laboratory with the same means. Recent experimental results on Fe15+ and Fe16+ from the Linac Coherent Light Source (LCLS) at SLAC and the synchrotron BESSY II will be presented. The data help to solve open astrophysical questions related to the plasma dynamics in X-ray binaries.
Date: Tue, 08.11.2011
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. Friedrich Aumayr

g-2 and ∆α (M_Z^2): touchstone of the Standard Model, keyhole to New Physics?
Speaker:Thomas Teubner (Liverpool Univ.)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Tue, 08.11.2011
Time: 17:00
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock, 1090 Wien
Contact:A. Hoang, H. Neufeld

Inequalities between area, angular momentum, charge and the cosmological constant for marginally trapped surfaces”
Speaker:Walter SIMON (Univ.Wien)
Abstract:im Rahmen des Literaturseminars
Date: Thu, 10.11.2011
Time: 14:15
Duration: 60 min
Location:Arbeitsgruppe: Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock
Contact:R. Beig

Obtaining weak and other eccentric values with non-ideal measurements
Speaker:Alex MATZKIN (CNRS/Univ. Cergy-Pontoise, Paris)
Date: Fri, 11.11.2011
Time: 15:30
Location:Hörsaal Atominstitut, Stadionallee 2, 1020 Wien
Contact:Y. Hasegawa