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Seminar of Department of Experimental Physics - Martin Žemlička (13.5.2022)

Frantisek.Herman@fmph.uniba.sk — Tue, 03 May 2022 16:06:00 +0200

Martin Žemlička (IST Austria):
Compact vacuum gap transmons - selective and sensitive probes for superconductor surface losses

Abstract:
The large capacitor of state-of-the-art transmon qubits systematically lowers the coupling to parasitic losses localized in material interfaces, but it also lowers the achievable integration density of quantum processors, and increases unwanted radiation losses, cross-couplings and leakage. We fabricate and characterize transmons with a footprint area as low as 36 x 39 μm2 and show that the interaction with the lossy dielectric interfaces is rapidly decreased by using very narrow (≥ 100 nm) capacitor vacuum gaps. We utilize commercial silicon-on-insulator wafers, where the sidewalls of suspended silicon beams are metalized by angle evaporation such that up to 99.6% of the electric field energy is distributed in vacuum and the effective dielectric constant is close to unity. Measuring the internal quality factor of lumped element resonators and the energy relaxation time of qubits hence allows to precisely probe the superconductor surface loss properties and isolate a single loss channel – two level defects in the aluminum surface oxide exposed to ambient conditions. This offers new means to systematically improve coherence times by testing appropriate superconducting materials and surface treatments.

EXAMINATION PERIOD SUMMER SEMESTER AR 2021/2022

Tue, 03 May 2022 16:00:00 +0200

The examination period of the summer semester will take place in the period from May 16, 2022 to June 30, 2022. During the last week of the teaching part of the semester from May 9, 2022 to May 13, 2022, examination pre-terms can be announced.

Seminar of Graph Theory - František Kardoš (5.5.2022)

Martin.Skoviera@fmph.uniba.sk — Tue, 03 May 2022 15:47:00 +0200

František Kardoš:
Strengthening a theorem of Meyniel Abstract:
For an integer k>=1 and a graph G, let K_k(G) be the graph that has vertex set all proper k-colorings of G, and an edge between two vertices x and y whenever the coloring y can be obtained from x by a single Kempe change. A theorem of Meyniel from 1978 states that K_5(G) is connected, with diameter O(5^|V(G)|), for every planar graph G. We significantly strengthen this result, by showing that there is a positive constant c such that K_5(G) has diameter O(|V(G)|^c) for every planar graph G. This is a joint work with Quentin Deschamps, Carl Feghali, Clément Legrand-Duchesne, and Théo Pierron. More information

RESULTS OF ELECTIONS OF THE CANDIDATE FOR THE DEAN OF COMENIUS UNIVERSITY, FACULTY OF LAW

Thu, 05 May 2022 21:15:00 +0200

The Electoral Commission for the Election of the Candidate for Dean of Comenius University in Bratislava, Faculty of Law organized at Comenius University in Bratislava, Faculty of Law (hereinafter referred to as the "Electoral Commission") announces that in the election of the candidate for Dean of Comenius University in Bratislava, Faculty of Law, as of April, 29, 2022, at 9 PM which took place in room No. 324 (IURIDICUM), a candidate elected as the candidate for Dean of Comenius University in Bratislava, Faculty of Law is - Assoc. Prof. Eduard Burda, Ph.D. The Electoral Commission for the Election of the Candidate for Dean of Comenius University in Bratislava, Faculty of Law states that the elections were conducted in compliance with the internal regulations of Comenius University in Bratislava, Faculty of Law, the internal regulations of Comenius University in Bratislava, and generally binding legal regulations of the Slovak Republic. In Bratislava, on April 29, 2022 Assoc. Prof. Marek Domin, Ph.D.
Chairman
The Electoral Commission for the Election of the Candidate for Dean of Comenius University in Bratislava, Faculty of Law

Seminar on Qualitative Theory of Differential Equations - Philippe Souplet (5.5.2022)

Pavol.Quittner@fmph.uniba.sk — Fri, 29 Apr 2022 11:31:00 +0200

Philippe Souplet (Université Sorbonne Paris Nord):
Universal estimates and Liouville theorems for superlinear problems without scale invariance
More information

43rd Student Scientific Conference

Fri, 29 Apr 2022 11:01:00 +0200

Comenius University Supports SUPPORTS YOUNG RESEARCHERS

Fri, 29 Apr 2022 10:13:00 +0200

This year, Comenius University Bratislava continues its long-standing tradition of financially...

EU COMMISSIONER REYNDERS AT THE LAW FACULTY OF COMENIUS UNIVERSITY IN BRATISLAVA

Thu, 05 May 2022 21:21:00 +0200

On 28 April 2022, a discussion with EU Commissioner Didier Reynders, Commissioner for Justice, was held in the Auditorium Maximum room of Comenius University in Bratislava, Faculty of Law (hereinafter referred to as the “Faculty of Law”). In his position, he is responsible for ensuring the rule of law within the EU; for improving the enforcement of judgments of the Court of Justice of the EU in the event of a breach of the rule of law; for improving judicial cooperation and the exchange of information between the competent authorities in the field of justice; for maximizing the potential of the use of new digital technologies in the judiciary; for consumer protection and the protection of their rights; for ensuring full implementation and performance of GDPR, etc. The discussion was co-organized with the Representation of the European Commission in Slovakia. The discussion was attended by Dean of the Faculty of Social and Economic Sciences, Assoc. Prof. Lucia Mokrá, Dean of the Faculty of Law, Assoc. Prof. Eduard Burda, employees of the Faculty of Law, as well as bachelor's, master's and doctoral students at Comenius University in Bratislava, Faculty of Law, and Faculty of Social and Economic Sciences . The discussion was opened by the head of the Representation of the European Commission in Slovakia, Prof. Šucha, who welcomed all those present and introduced by Mr. Reynders and gave the floor to the Vice-Dean of the Faculty of Law, Comenius University in Bratislava, Dr. Andrea Szakács. She welcomed those present on behalf of the Faculty of Law and then gave the floor to Mr. Reynders. At the beginning of the discussion, Mr. Reynders informed about the war in Ukraine, the state of the rule of law in Slovakia, etc. Later, Mr. Reynders responded to questions from the auditorium that fell within his responsibilities. They concerned, e.g., misleading information, so-called hoaxes, and hate speech on social networks and instruments adopted by the EU to address these negative facts; issues of national identity protection and whether it has the potential to jeopardize further EU integration; political situation in Hungary and Poland, as Eurosceptics; possible follow-up infringement proceedings under Article 260 of the Treaty on the Functioning of the EU, unanimous versus majority voting as obstacles to the rule of law, etc. The discussion was very fruitful with well-founded and inspiring questions. We believe that this was not the last visit by the Commissioner, and we look forward to his meeting again.

Seminar of Department of Theoretical Physics - André Sopczak (3.5.2022)

Peter.Matak@fmph.uniba.sk — Thu, 28 Apr 2022 10:57:00 +0200

Dr. André Sopczak (IEAP CTU in Prague, Czech Republic):
Higgs Boson Coupling to Top Quarks and Self-coupling Measurements Abstract:
Ten years after the discovery of the Higgs boson, precision measurements of the properties of the Higgs boson are at the forefront of research. Fundamental predictions of the Higgs theory are the strong coupling to top quarks and the Higgs boson self-coupling. In this presentation, experimental results and sensitivity expectations are discussed. Furthermore, an outlook is given to related searches for New Physics. More information

Nuclear Seminar - Natália Džalaiová (4.5.2022)

Jaroslav.Stanicek@fmph.uniba.sk — Thu, 28 Apr 2022 10:46:00 +0200

Mgr. Natália Džalaiová:
Strangeness production in Xe–Xe collisions at √sNN = 5.44 TeV with the ALICE experiment at the LHC
Abstract:
One of the leading areas of high-energy physics studies is the study of a strongly interacting matter, quark-gluon plasma (QGP). Strangeness enhancement is originally proposed as a signature of such a state. In this work, the production of multi–strange (Ξ− and Ω− ) baryons and their anti-particles measured by ALICE at LHC in Xe–Xe collisions at √sNN = 5.44 TeV is investigated. The pT spectra obtained at mid-rapidity have been studied in interval 0.6 < pT < 5 GeV/c and 1 < pT < 5 GeV/c, respectively, with centrality varying from the most central to the most peripheral collisions (up to 90%). Comparison of obtained data with pp, p–Pb and Pb–Pb systems would help to investigate the microscopic origin of enhanced strangeness production, which is not known yet.