CPT

Calendar of Physics Talks Vienna

How to squeeze light into the nano-scale: putting the nano into photonics
Speaker:Jeremy J. Baumberg, FRS (NanoPhotonics Centre, Cavendish Laboratory, University of Cambridge)
Abstract:Generations of students have been taught that light can be focussed down only as tight as a spot on the order of its wavelength. This several hundred nanometer scale limit would imply that nano-scale active elements cannot interact strongly with light. However this is untrue. Here we demonstrate the localisation of light tighter than 1nm. This has two principal benefits: spectroscopy can be used to probe such nano-scale architectures, and light can be concentrated to high intensity in ultra-small volumes. Both these have utility in a variety of new applications, which open up other areas of science. The key component for such manipulation of light is the intricate 3D construction of metallic composites. While current technologies for fabricating such nanostructures (for instance in electronics or IT) depend on surface lithographies, these are not well suited to the task as they are expensive, slow, inadequate for three dimensions, and ineffective. Thus a secondary focus of our work is the use of nano self-assembly to control rapid construction on the nanoscale. Such work goes hand in hand with our capabilities to measure what we have made through optics sensing. References: see http://www.np.phy.cam.ac.uk/publications/ [1] “Precise sub-nm plasmonic junctions within gold nanoparticle assemblies using cucurbit[n]uril ‘glue’”, RW Taylor et al., ACS Nano 5, 3878 (2011) [2] “Scalable Cylindrical Metallo-dielectric Metamaterials”, N. Gibbons et al., Advanced Materials 21, 3933 (2009) [3] “3D Optical Metamaterial Made by Chiral Self-Assembly”, S Vignolini et al, Nature (2011)
Date: Mon, 24.10.2011
Time: 17:00
Location:TU Wien Freihaus, Hörsaal 5, 2. Stock (grüner Bereich)
Contact:J. Schmiedmayer

Local bulk physics in the AdS/CFT correspondence
Speaker:Michael Gary (TU Wien)
Abstract: I will review the AdS/CFT correspondence, motivating the duality from the perspective of the black hole information problem. After a thorough introduction, I will explain a test of the holographic nature of the correspondence and show higher dimensional local physics emerging in the limit that the AdS radius becomes large (equivalently, $N_c\rightarrow\infty$). If time allows, I will talk about obstructions to the construction at finite N.
Date: Tue, 25.10.2011
Time: 12:30
Duration: 60 min
Location:TU Wien (Wiedner Hauptstr. 8-10), yellow area, 10th floor, seminar room E136
Contact:Sabine Ertl

Infinite spin representations and deformations
Speaker:Christian Köhler (Univ.Wien)
Abstract:im Rahmen des Seminars für Mathematische Physik
Date: Tue, 25.10.2011
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:J. Yngvason

In-vivo structural and functional optical coherence microscopy
Speaker:Ao.Univ.Prof. Dr. Rainer A. Leitgeb (Center for Medical Physics and Biomedical Engineering, Medical University Vienna)
Abstract:Optical Coherence Tomography (OCT) has found entrance into many different fields of medicine and shows also interesting applications in the field of biology. Especially Fourier domain (FD) OCT offers distinct advantages with respect to imaging speed and sensitivity. Recent advances in light source and detector technology propelled imaging speeds of FDOCT from several 100.000 to even several Mhz depth profile rate. This acquisition speed allows already recording several tissue volumes per second! Motion artifacts that usually affect in-vivo applications are strongly reduced which increases image quality revealing comprehensive micro-structural details, and paves the way for in-vivo optical coherence microscopy (OCM). High speed FDOCM gave for example for the first time access to photoreceptor structure without employing adaptive optics. The structural fidelity proves important as well for imaging micro-capillary structure of the central retina. The capillary structure is highly susceptible to pathologic changes of microcirculation that might be the cause of e.g. diabetes. Recent developments of non-invasive optical angiography demonstrate impressive examples of contrasting tumor perfusion or retinal perfusion. In particular, employing Bessel beams with their regenerative property and large depth of focus offer substantial advantages or imaging small details such as micro-capillaries within strongly scattering tissue. There is substantial hope that the number of invasive contrast agent based angiography techniques could be reduced. Again high speed imaging decreases measurement time resulting in increased patient comfort as well as reduces motion artifacts resulting in higher functional and structural fidelity.
Date: Tue, 25.10.2011
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. Martin Gröschl

Mass effects in perturbative QCD
Speaker:Ingo Schienbein (LPSC, Grenoble)
Abstract:im Rahmen des Teilchenphysikseminars
Date: Thu, 27.10.2011
Time: 14:15
Duration: 60 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, H. Neufeld

Cosmological spacetimes with regular lattices of black holes
Speaker:Mikolaj Korzynski (Univ.Wien) (Fakultät für Physik)
Abstract:im Rahmen des Literaturseminars
Date: Thu, 27.10.2011
Time: 14:15
Duration: 60 min
Location:Arbeitsgruppe: Gravitation, Währinger Strasse 17, Seminarraum A, 2. Stock
Contact:R. Beig

A Framework for Local Thermodynamic Equilibrium in Relativistic Quantum Field Theories
Speaker:Jan Schlemmer (Univ. Wien)
Abstract:im Rahmen der gemeinsam veranstalteten Seminare "Komplexe Stochastische Systeme" (Univ. Wien) und "Analyse Komplexer Systeme" (Medizinische Univ. Wien)
Date: Fri, 28.10.2011
Time: 14:15
Duration: 90 min
Location:Fakultät für Physik, Erwin Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock, 1090 Wien
Contact:H. Hüffel, Stefan Thurner