CPT

Calendar of Physics Talks Vienna

The functorial axiomatization of topological quantum field theory (Vienna Theory Lunch Seminar)
Speaker: Tim Lüders (Universität Wien)
Abstract:In this talk, I will give a lightning introduction to topological quantum field theory in its functorial axiomatization, due to Atiyah and Segal. We start by exploring the very basics of the mathematical discipline of category theory, which will then be used as a convenient tool to package essential properties of Feynman’s path integral into a mathematically rigorous framework. Examples of physical theories that can be described in this setting include Chern-Simons theory as well as topological sigma and state sum models. I will finish the talk by mentioning several natural generalizations of the introduced mathematical structures, and what physical interest each of them carries. [[part of the "Vienna Theory Lunch Seminar, see https://lunch-seminar.univie.ac.at ]]
Date: Tue, 05.03.2024
Time: 12:30
Duration: 75 min
Location:University of Vienna, Boltzmanngasse 5, 5th floor, Schrödinger Lecture Hall
Contact:Florian Lindenbauer

Quasinormal modes of black holes in classical and alternative theories of gravity
Speaker:Angel Rincon (Universidad de Alicante)
Abstract:In this talk, we study neutral massless/massive scalar field perturbations around different black hole backgrounds in several dimensions. We reduce the problem to its Schroedinger-like form, obtain the effective potential, and then calculate the corresponding quasinormal modes. For well-behaved black holes, we take advantage of the WKB method to obtain the spectrum. As usual, the quasinormal modes depend on the parameters of the black hole, so by varying them we can see how their variations affect the Quasi Normal frequencies.
Date: Tue, 05.03.2024
Time: 14:00
Duration: 60 min
Location:Erwin Schroedinger-Hoersaal (Boltzmanngasse 5, 5th floor)
Contact:Adrien Fiorucci, Benjamin Koch, Daniel Grumiller

Nano-Printing using Charged Particle Beams: Precursors, Processing and Hybrid Approaches
Speaker:Sven Barth (Physics Institute, Goethe University Frankfurt/Germany Inorganic Chemistry Institute, Goethe University Frankfurt/Germany)
Abstract:The vast field of additive manufacturing includes true nano-printing techniques based on charged particle beams of ions and electrons. Besides applications such as mask repair in semiconductor industry, further development of precursor chemistry and writing techniques will enable fundamental studies of shape-dependent phenomena and the fabrication of functional nanostructures on literally any surface. This talk will introduce focused electron/ion beam deposition (FEBID/FIBID) techniques as a very convenient for the spatially controlled formation of pure metals and more complex compositions. The basics of the processes will be outlined [1] and specific examples of FEBID/FIBID-derived material will be presented.[2-4] Moreover, the influence of precursor chemistry, deposition strategy and post-growth processing on the deposit’s composition and physical properties will be discussed. Finally,
Date: Tue, 05.03.2024
Time: 16:00
Location:TU Wien, Institut für Angewandte Physik, E134 1040 Wien, Wiedner Hauptstraße 8-10 Yellow Tower „B“, 5th floor, SEM.R. DB gelb 05 B
Contact:Prof. Amalio Fernandez-Pacheco Chicon

Analogue Quantum Simulators - table-top experiments for quantum field theory
Speaker:Sebastian Erne (TU Wien, Atominstitut)
Abstract:Analogue (quantum) simulators have gained increasing traction over the last decade as an interdisciplinary branch between experimental and theoretical physics. They present an ideal platform to study fundamental questions of quantum field theory, which are otherwise not or only indirectly accessible in experiments. After giving an introduction to analogue gravity and cosmology based on classical and quantum fluids, I will present recent results of our research on analogue QFT simulators in and beyond the linear regime of the sine-Gordon model. The aim of this talk is to give an overview of the general ideas behind continuous (quantum) field theory simulators based on ultracold atom systems, and the opportunities these offer for the experimental exploration of QFT in flat and curved spacetime.
Date: Wed, 06.03.2024
Time: 16:15
Duration: 45 min
Location:Helmut Rauch Hörsaal ATI
Contact:Maximilian Prüfer

Comparing fermionic superfluids in two and three dimensions
Speaker:Henning Moritz (University of Hamburg)
Abstract:Understanding the origins of unconventional superconductivity has been a major focus of condensed matter physics and experiments have found the highest critical temperatures in layered 2D materials. However, to what extent the remarkable stability is affected by their reduced dimensionality is still an open question. Here, I will discuss influence of dimensionality on the stability of strongly interacting fermionic superfluids. I will introduce fermionic superfluidity in ultracold atoms, where Cooper pairs forms. Their pair size can be continuously tuned from the Bardeen-Cooper-Schrieffer (BCS) regime of loosely bound pairs to the BEC regime of very tightly bound pairs [1]. I will introduce the critical velocity vc and the pairing gap Δ and review milestone experiments performed on superfluid 3D Fermi gases [2]. After explaining how to determine vc and Δ using Bragg spectroscopy I will d
Date: Fri, 08.03.2024
Time: 10:00
Duration: 45 min
Location:Helmut Rauch Hörsaal ATI
Contact:Julian Leonard