Calendar of Physics Talks Vienna

Cavity quantum electrodynamics with carbon nanotubes: from atomic-like systems to condensed matter.
Speaker:Takis Kontos (Laboratoire Pierre Aigrain, Ecole Normale Supérieure-PSL Research University, CNRS, Université Pierre et Marie Curie-Sorbonne Universités, Université Paris Diderot-Sorbonne)
Abstract:Cavity quantum electrodynamics techniques have turned out to be instrumental to probe or manipulate the electronic states of nanoscale circuits. Recently, cavity QED architectures have been extended to quantum dot circuits. These circuits are appealing since other degrees of freedom than the traditional ones (e.g. those of superconducting circuits) can be investigated. I will show how one can use carbon nanotube based quantum dots in that context. In particular, I will focus on the coherent coupling of a single spin [1] and the strong coupling of a hybrid superconductor quantum dot circuit to cavity photons. Quantum dots also exhibit a wide variety of many body phenomena. The cQED architecture could also be instrumental for understanding them. One of the most paradigmatic phenomenon is the Kondo effect which is at the heart of many electron correlation effects. I will show that a cQED ar
Date: Mon, 13.06.2016
Time: 16:00
Duration: 60 min
Location:TU Wien, HS 7 Schütte-Lihotzky, Karlsplatz 13
Contact:www.coqus.at / Christina Becker

The first direct detection of Gravitational Waves and beyond.
Speaker:Fulvio Ricci (Dipartimento di Fisica Università di Roma Sapienza)
Abstract:The direct detection of Gravitational Waves opens a new windows to look at the Universe. This great success is the result of a long experimental effort ended with the construction of the second generation of GW detectors. These advanced instruments, installed in USA and Europe, employee high sensitive laser interferometry to probe the fundamental nature of gravity and the history and future of the Universe. LIGO in USA, and Virgo in Europe are the backbone of a network, which will be expanded soon with the addition of the Japanese interferometer KAGRA. In this talk we report the results obtained during the first scientific run of the network when just the two LIGO interferometers were running. Then, we will review the scientific perspectives of the network paying attention on the noise sources limiting its sensitivity. The scientific community has already started a study aimed to a further increase of the detector sensitivity for the next (3rd) Earth-based generation detector (ET).Thus, we will conclude by reporting the new ideas for the second phase of advanced detectors and for the ET project.
Date: Mon, 13.06.2016
Time: 17:30
Location:TU Wien-Freihaus, Hörsaal 5, 2. Stock, grüner Bereich
Contact:J. Schmiedmayer

Modelling surface photo-electrochemistry: beyond the computational hydrogen electrode
Speaker:Harald Oberhofer (Theoretical Chemistry, TU Munich, Germany)
Abstract:The role, computer-modelling plays today in understanding and optimising catalysts for photo-electrochemical reactions, is undisputed. Yet, state of the art simulation approaches tend to rely on a number of assumptions and simplifications, which – according to newest results – may not be fully justified. For example, simulation of the all-important electro-catalytic water oxidation reaction is mainly based on idealised surfaces and the computational hydrogen electrode (CHE) approach, which evaluates the thermodynamic feasibility of a catalyst looking at pathway where each hydrogen abstraction is coupled to the removal of one electron (PCET). This in turn is used to justify neglecting solvation effects as only overall neutral reaction intermediates need to be considered. Yet, especially on semi-conducting catalysts the assumption of PCET is not necessarily fulfilled. The great success of
Date: Tue, 14.06.2016
Time: 16:00
Location:Technische Universität Wien, Institut für Angewandte Physik, E134 yellow tower „B“, 5th floor, Sem.R. DB gelb 05 B (room number DB05L03) 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Univ.Prof. Dr. Ulrike Diebold

Black holes with internal structure and avoidance of singularities
Speaker:Diego Rubiera-Garcia (Lisbon)
Abstract:We consider black hole geometries in metric-affine extensions of GR, where no a priori constraint between metric and connection is introduced. Working with several gravitational actions we show that this formulation of modified gravity yields ghost-free and second-order field equations of motion. When applied to electrovacuum space-times, the point-like singularity of GR is generically replaced by a internal, finite-size structure with the same properties as a wormhole. Though curvature divergences may arise at the wormhole throat, we show the geodesically complete character of these space-times. The regularity of these space-times is further discussed in terms of congruence of geodesics and scattering of waves off the wormhole.
Date: Fri, 17.06.2016
Time: 13:00
Duration: 60 min
Location:Seminar room DB gelb 03, 3rd floor, TU Wien, Wiedner Hauptstr. 8-10, 1040 Vienna
Contact:Daniel Grumiller and Johanna Knapp