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Calendar of Physics Talks Vienna
| Erwin Schroedinger Lecture: Photonic quantum computing -- a bright future for many applications |
| Speaker: | Prof. Philip Walther (University of Vienna) |
| Abstract: | The precise quantum control of single photons, together with the intrinsic advantage of being mobile make optical quantum system ideally suited for quantum information applications that require communication or the delegation of tasks. Examples include quantum cryptography as well as quantum clouds and quantum computer networks.
I present the current architectures for scalable photonic quantum computers and special purpose applications that exploit advantages of photonic quantum system. This is shown by examples for various quantum computations such as quantum machine learning and in particular reinforcement learning, in addition to secure quantum and classical computing tasks that require quantum networks. I will discuss technological challenges for the scale up of photonic quantum computers and remarkable opportunities for special-purpose applications such as neuromorphic circuits. |
| Date: | Mon, 12.12.2022 |
| Time: | 17:00 |
| Duration: | 60 min |
| Location: | Erwin Schroedinger Institut, Boltzmann Lecture Hall |
| Contact: | Erwin Schroedinger Institut |
| Wien Winter Workshop on Solid-State Spectroscopy: Part 1 |
| Speaker: | A. Shuvaev, D. Szaller, J. Deisenhofer, J. Vit |
| Abstract: | 14:00-15:30 Alexey Shuvaev (TU Wien) Magnons and electromagnons in cycloidal incommensurate antiferromagnet (Landau-Lifshitz equation, classical spin-wave theory, Heisenberg Hamiltonian)
15:30-17:00 Dávid Szaller (TU Wien). Quantum-mechanical description of spin-waves in real materials (Heisenberg antiferromagnets, spin-streching modes, numerical methods)
17:00-17:30 Coffee break
17:30-18:30 Joachim Deisenhofer (University of Augsburg). Vacuum Rabi-oscillations in some magnets and beyond (vacuum-Rabi oscillations in THz time-domain spectra of antiferromagnets, "cavity-QED" effects observed without a cavity)
18:30-19:15 Jakub VÃt (Institute of Physics of the Czech Academy of Sciences, Prague) Experiments using intense THz radiation
(laser-based table-top vs. linear-accelerator-based THz sources, probing techniques following THz pump, quantitative data evaluation) |
| Date: | Tue, 13.12.2022 |
| Time: | 14:00 |
| Duration: | 300 min |
| Location: | Fachgruppenraum Physik (Freihaus, 1st floor yellow) |
| Contact: | Andrei Pimenov |
| Distracted by Science-Fiction: The Physics of Reverse-Engineered Metrics |
| Speaker: | Sebastian Schuster (Charles University, Prague) |
| Abstract: | Reverse-engineered metrics are ad-hoc metrics; instead of using the Einstein equation to solve for a metric given a stress-energy tensor as input,the metric is the input and the stress-energy tensor the output. Much of the attention is taken up by metrics inspired by science fiction:Wormholes, warp drives, tractor beams. Historically, however, this was not the case, as both the Gödel universe and regular black holes are similarly reverse-engineered.The goal of this talk will be to demonstrate how the mathematical simplicity (differentiation instead of integration) is gained through physical difficulty. Usually this is reduced to a question of physicality.Worse this question is then in turn answered in an oversimplified way by invoking (point-wise) energy conditions. I will demonstrate why energy condition cannot easily separate the physical wheat from the metric chaff and how . . . |
| Date: | Tue, 13.12.2022 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock |
| Contact: | S. Fredenhagen, D. Grumiller, E. Battista, R. Ruzziconi |
| Wien Winter Workshop on Solid-State Spectroscopy: Part 2 |
| Speaker: | P. Balla, E. Constable |
| Abstract: | 10:00-11:30 Péter Balla (Wigner Research Centre for Physics, Budapest) Group theory and spins. (Symmetries in quantum mechanics as applied to spins; multipoles, dynamics and selection rules)
11:40-13:10 Evan Constable (TU Wien, Institute of Solid State Physics) Neutron scattering theory and techniques
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| Date: | Wed, 14.12.2022 |
| Time: | 10:00 |
| Duration: | 180 min |
| Location: | Hörsaal 4 (Freihaus, 2nd floor yellow) |
| Contact: | Andrei Pimenov |
| X-ray spectroscopy of highly charged ions with synchrotron light sources |
| Speaker: | Dr. Rene Steinbruegge (Heidelberger Ionenstrahl-Therapiezentrum, Universitaetsklinikum Heidelberg) |
| Abstract: | The properties of electronic transitions in highly charged ions are important for modelling hot plasmas, testing quantum electrodynamic calculations and applications in metrology. By combining an electron beam ion trap (EBIT) with monochromatized x-rays from synchrotron radiation sources, these transitions can be resonantly excited, providing a direct way of investigating them.
I will present measurements using the compact PolarX-EBIT, which was designed specifically for the use at synchrotron light sources. In multiple campaigns, we measured... [full abstract available here: https://indico.cern.ch/event/1227038/] |
| Date: | Wed, 14.12.2022 |
| Time: | 17:00 |
| Duration: | 60 min |
| Location: | SMI Seminarraum, Kegelgasse 27, 3. Stock (online participation possible: request zoom link before 12:00 of Dec 14th via email martin.simon at oeaw.ac.at) |
| Contact: | Eberhard Widmann, Martin Simon |
| On the propagation of gravitational waves: diffraction, dispersion & birefringence |
| Speaker: | Miguel Zumalacárregui (Albert Einstein Institute, Potsdam) |
| Abstract: | Just like light,gravitational waves(GWs)are deflected and magnified by the large-scale structure of the Universe,a phenomenon known as gravitational lensing.Their low frequency,phase coherence and capacity to propagate with no absorption makes GWs an ideal signal in which to observe wave-propagation phenomena.I will describe how GWs deflected by cosmic structures produce diffractive, wave-optics phenomena, whose measurement will allow us to infer the properties of galactic and dark matter halos.For GWs in strong gravitational fields,such as the vicinity of a massive black hole, their propagation depends on the frecuency (dispersion) and polarization(birefringence)through the gravitational spin-hall effect.I will describe how observations of sources near central black holes of galaxies may enable the observation of dispersive GWs. While birefringence might be too suppressed to observe ... |
| Date: | Thu, 15.12.2022 |
| Time: | 15:15 |
| Duration: | 60 min |
| Location: | https://univienna.zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09 |
| Contact: | P. Chrusciel, D. Fajman |
| A higher-spin symmetry algebra in asymptotically flat space-time |
| Speaker: | Simon Pekar (University of Mons) |
| Abstract: | We discuss the generators of gauge transformations of Fronsdal theory in flat space-time in any dimension (at least 3) and explicitly construct a non-Abelian symmetry algebra on the vector space they span, to be interpreted as a candidate gauge algebra for an interacting higher-spin theory in flat space. To this end, we use a coset construction by taking the quotient of the universal enveloping algebra of space-time isometries by a certain ideal, and prove the unicity of this construction. We then show how to understand this ideal by a holographic argument using the higher symmetries of a Carrollian scalar field, and provide an extension to an asymptotic symmetry algebra. We conclude by discussing potential applications to flat higher-spin holography. |
| Date: | Thu, 15.12.2022 |
| Time: | 16:00 |
| Duration: | 60 min |
| Location: | Zoom: Meeting ID: 950 0240 9522 |
| Contact: | Romain Ruzziconi, Daniel Grumiller, Iva Lovrekovic |
| Thermal fate and many-body parametric resonances in driven sine Gordon model |
| Speaker: | Roberta Citro (Università degli Studi di Salerno) |
| Abstract: | Integrable systems are expected to not thermalize, but is still an open question if interactions and mode coupling at long times can let the system reach the infinite temperature limit. The questions I will address in this talk are how an integrable quantum system breaks the non-ergodicity and undergoes the thermal fate and how the mode coupling appears at long times. I will give some answers for the many-body Kapitza pendulum and the parametric harmonic oscillator, the so-called driven sine-Gordon model. I will also discuss a proposal for experiments with cold atoms. |
| Date: | Fri, 16.12.2022 |
| Time: | 10:00 |
| Duration: | 60 min |
| Location: | TU Wien, Atominstitut |
| Contact: | Jörg Schmiedmayer |
| Thermal fate and many-body parametric resonances in a driven sine Gordon model |
| Speaker: | Roberta Citro (University of Salerno, IT) |
| Abstract: | Integrable systems are expected to not thermalize, but it is still an open question if interactions and mode coupling at long times can let the system reach the infinite temperature limit. The questions I will address in this talk are how an integrable quantum system breaks the non-ergodicity and undergoes the thermal fate and how the mode coupling appears at long times. I will give some answers for the many-body Kapitza pendulum and the parametric harmonic oscillator, the so-called driven sine-Gordon model. I will also discuss a proposal for experiments with cold atoms. |
| Date: | Fri, 16.12.2022 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | ATI HÃÂörsaal/https://tuwien.zoom.us/j/93672218922?pwd=dEZNQ2liVzRNNURvNmVWVE5KUWRiQT09 |
| Contact: | Jörg Schmiedmayer |
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