CPT

Calendar of Physics Talks Vienna

High-temperature superconductivity and where to find it (Vienna Theory Lunch Seminar)
Speaker:Paul Worm (TU Wien)
Abstract:I will give a theoretical perspective on high-temperature superconductors, with a special focus on quasi-two-dimensional compounds like cuprates and nickelates. Specifically, I will review their electronic structure, how to construct effective low-energy Hamiltonians and approximate solutions of those. Implications for superconductivity are discussed along the way. [[This talk is part of the "Vienna Theory Lunch Seminar", a weekly seminar aimed at both graduate and advanced undergraduate students, jointly organized by the University of Vienna and TU Wien. The focus of the seminar is on recent theoretical research done by Master students, PhDs and PostDocs. Free lunch (pizza) will be provided at the seminar. For more information please visit our web page: https://lunch-seminar.univie.ac.at, where you can also subscribe to our mailing list.]]
Date: Tue, 10.10.2023
Time: 12:30
Duration: 75 min
Location: TU Wien: Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room DB10E11
Contact:Florian Lindenbauer

Exact pp-wave solutions in chiral higher spin gravity
Speaker:Tung Tran (University of Vienna)
Abstract:We derive exact pp-wave solution of chiral HSGRA using free differential algebra (FDA) approach a la Newman-Penrose formalism. We then generalize this result to pp-wave-like higher-spin solutions of chiral higher-spin gravity (HSGRA) and show that linear solutions are, remarkably, also the solutions of the full non-linear system of chiral-FDA. Our results show that massless chiral higher-spin gauge fields can propagate on any Petrov type-N pp-wave background despite the fact that chiral HSGRA does not have the standard Einstein-Hilbert term in its action.
Date: Tue, 10.10.2023
Time: 14:00
Duration: 60 min
Location:Seminar-Raum DB gelb 03 TU Wien, Wiedner Hauptstraße 8-10
Contact:S. Fredenhagen, D. Grumiller, H. Steinacker, R. Ruzziconi

Error-robust implementations of Quantum Signal Processing using Rydberg atoms [1]
Speaker:Sina Zeytinoglu (NTT Research (Japan))
Abstract:Reducing the errors induced by gate implementations is crucial for building reliable quantum computers out of externally controlled quantum devices. An experimentalist attempting to control a microscopic quantum mechanical device harnesses the interactions between the device and its environment, an act that inevitably induces errors. Hence, an overarching goal of quantum control theory has been developing error-robust control protocols that leverage the structure of small-scale quantum systems to reduce gate-induced errors. However, until recently, employing a similar strategy for large-scale quantum systems was infeasible because of a lack of known general structures describing quantum algorithms, let alone those that can be leveraged for error-robust implementations. Here, we design error-robust implementations of a broad range of quantum algorithms by studying the structures unveiled
Date: Tue, 10.10.2023
Time: 15:00
Duration: 45 min
Location:Helmut Rauch Hörsaal ATI
Contact:Paul Erker

Studying 2D metal-organic frameworks on weakly-interacting surfaces: How the support defines the system properties
Speaker:Zdenek Jakub (Central European Institute of Technology (CEITEC) Brno/CZ)
Abstract:Two-dimensional metal-organic frameworks (2D MOFs) show great potential for applications in single-atom catalysis, spintronics, or high-density data storage. The functionality of these materials crucially depends on the local environment of the embedded metal atoms, and such atomic-scale details are experimentally best ascertained on 2D MOFs supported on atomically flat surfaces. However, the interaction with the support can change the 2D MOF properties, which limits the relevance of on-surface studies for applications. In this talk I will show that this issue can be circumvented by synthesizing 2D MOFs on an inert graphene support, where the intrinsic 2D MOF properties can be partially retained. We demonstrate this on the case of metal-TCNQ 2D MOF systems (TCNQ = tetracyanoquinodimethane), which can adopt non-planar configuration with metal atoms in quasi-tetrahedral sites when supporte
Date: Tue, 10.10.2023
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:Univ.Prof. G. Parkinson

Medium modifications to jet angularities
Speaker:Ankita Budhraja (NIKHEF, Amsterdam)
Abstract:When a high energy parton traverses the medium (QGP), it undergoes multiple interactions with the medium constituents leading to a modification of its radiation pattern. By utilizing jet angularity measurements on such a jet,one can control the sensitivity of the observable to collinear emissions in the jet through a continuous parameter a,with a<2. We utilise the framework of SCET with Glauber gluons (SCETG) to study medium effects on ungroomed angularity distributions for the range a<1. Within SCETG, the jet-medium interactions are incorporated by off-shell Glauber gluons generated from the color charges in the medium.We find that, in the medium, the angularity distributions are narrower and have a steeper fall compared to the vacuum ones. I will provide a qualitative understanding of this apparent narrowing effect in the medium,consistently within the SCETG framework.
Date: Tue, 10.10.2023
Time: 16:15
Duration: 60 min
Location:Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, M. Procura

Static Black Binaries in de Sitter
Speaker: Jorge Santos (Cambridge)
Abstract:We construct the first four-dimensional multi-black hole solution of general relativity with a positive cosmological constant. The solution consists of two static black holes whose gravitational attraction is balanced by the cosmic expansion. These static binaries provide the first four-dimensional example of non-uniqueness in general relativity without matter.
Date: Wed, 11.10.2023
Time: 14:15
Duration: 60 min
Location:ZOOM https://univienna.zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09
Contact:P. Chrusciel, D. Fajman