CPT

Calendar of Physics Talks Vienna

Life in lineland (on an atom chip)
Speaker:Dr. Klaasjan van Druten (WZI Universität Amsterdam)
Abstract:Quantum many-body physics in one dimension (1D) is remarkably different from that in 3D (and from that in 2D). In addition, exact solutions are available for some 1D quantum many-body systems, yielding the full quantum many-body eigenstates and the exact thermodynamics through a method known as the (thermodynamic) Bethe Ansatz (BA). The 1D Bose gas is the simplest example of a system that can be solved in this way. Atom chips (lithographically patterned structures to trap and manipulate quantum gases) offer an appealing and flexible means of creating and studying the 1D Bose gas. I will present our recent experiments, including the first experimental test of the thermodynamic BA using rubidium atoms on an atom chip [PRL 100, 090402 (2008)]. Further developments will also be discussed, including experiments on the two-component 1D Bose gas. For the latter system, the BA yields exact results only for the case of component-independent interactions, a situation that is almost realized in rubidium.
Date: Mon, 15.06.2009
Time: 17:30
Duration: 60 min
Location:Hörsaal des Atominstituts, Stadionallee 2, 1020 Wien
Contact:Prof. Jörg Schmiedmayer, Atominstitut

Vienna Theory Lunch Club - Mirror Symmetry
Speaker:Alexander Noll (TU Wien)
Abstract:Mirror symmetry is a duality between two string theories compactified on two different geometries. It has very interesting consequences: it allows one to compute correlation functions exactly, including instanton corrections, by relating them to certain computations which can be performed in the mirror theory. I will give a pedagocial introduction to the simplest case of mirror symmetry, namely T-duality for the closed bosonic string and explain the consequences. In particular, I will show that T-duality implies that there is a minimal length scale in string theory. I will then generalize the discussion to superstrings.
Overview Lunch Seminar
Date: Tue, 16.06.2009
Time: 12:30
Duration: 60 min
Location:University of Vienna, Boltzmanngasse 5, 5th Floor, Large Seminar Room
Contact:Max Attems, Daniel Grumiller, Beatrix Hiesmayr

Rotierende Bose-Gase im niedrigsten Landau-Level: "Composite-fermions" - Zustände
Speaker:Damian Draxler u. Ingo Fürede (Fakultät für Physik)
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Tue, 16.06.2009
Time: 14:30
Duration: 60 min
Location:Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:J. Yngvason

63Self-organized ripple patterns by ion erosion – experiment, theory, and application
Speaker:Adrian Keller (Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, Dresden/D)
Abstract:It is well known that oblique low and medium energy (typically 0.1 – 100 keV) ion erosion of solid surfaces can lead to the formation of periodic ripple patterns with wavelengths ranging from 10 to 1000 nm. These ripple structures have been found on a large variety of materials, including semiconductors, metals, and insulators. The formation and early evolution of the ripple patterns can be described by a linear continuum equation derived by Bradley and Harper. At longer times, however, nonlinear terms have to be taken into account, leading to nonlinear models based on the Kuramoto-Sivashinsky equation. This talk will provide an overview of ion-induced pattern formation and summarize the theoretical basics. Recent experimental results on the evolution of nanoscale ripple patterns on silicon surfaces during high-fluence ion sputtering will be presented and compared to the predictions of different continuum models. In addition, promising applications of nanorippled substrates as templates in thin film growth will be discussed.
Date: Tue, 16.06.2009
Time: 16:00
Location:Technische Universität Wien, Institut für Allgemeine Physik, Seminarraum 134A, Turm B (gelbe Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Ao. Univ.Prof. Dr. Friedrich Aumayr

Kaon Physics with Chiral Quarks
Speaker:Christopher T. Sachrajda (Southampton Univ.) (Fakultät für Physik)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Tue, 16.06.2009
Time: 16:15
Duration: 60 min
Location:Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:H. Neufeld

Strongly correlated phases in rapidly rotating Bose gases
Speaker:Robert Seiringer (Princeton University) (Fakultät für Physik)
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Wed, 17.06.2009
Time: 14:15
Duration: 60 min
Location:Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:J. Yngvason

Electron superhighways and bridges in protein complexes
Speaker:Barry Sanders (Calgary University)
Abstract:Does Natural Selection optimize biomachinery at the quantum level? Does quantum coherence play a role in biochemical electron transport? We show that a particular redox protein complex is configured so that metastable water bridges act as "superhighways" for coherent electron transport between its constituent protein molecules. The bridge enables fast coherent electron transport across the gap instead of dooming the electron to slow thermal hopping through the interprotein medium. Although our study focuses on a particular protein complex that has been frozen and characterized by crystallography, we conjecture that bridge-building is ubiquitous for redox processes.
Date: Fri, 19.06.2009
Time: 15:00
Location:Ernst-Mach-Hörsaal, 2. Stock, Strudlhofgasse 4, 1090 Wien
Contact:Prof. Anton Zeilinger (IQOQI)