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Calendar of Physics Talks Vienna
| Catalytic and Electrocatalytic Properties Investigated at the Atomic Scale by Surface Science : From Oxides to Single-Atom Catalysts |
| Speaker: | Jeppe Vang Lauritsen (Aarhus University, Denmark) |
| Abstract: | We pursue the goal of understanding fundamental properties of heterogeneous catalysts and electrocatalysts by focusing on what happens on the atomic level on surfaces. Surface science techniques, such as Scanning Probe Microscopy (STM) and X-ray Photoelectron Spectroscopy (XPS) are excellent methods in this regard, since they allow us to image surfaces in atomic detail and characterize the interaction with reactants â sometimes at elevated pressure conditions corresponding to catalytic conditions. In my talk, I will first give examples of how we use ambient-pressure scanning tunneling microscopy (STM) to investigate Cu surfaces in atomic detail. Cu(110) is not reactive to CO2 in vacuum conditions, but when the pressure is raised, the surface structure converts, leading to a high Cu mobility and creation of Cu-carbonate complexes. For CuZn/Cu(111), which is a candidate for the active surf |
| Date: | Tue, 14.05.2024 |
| Time: | 16:00 |
| Location: | TU Wien, Institut für Angewandte Physik, E134 1040 Wien, Wiedner HauptstraÃe 8-10 Yellow Tower âBâ, 5th floor, SEM.R. DB gelb 05 B |
| Contact: | Prof. Gareth Parkinson |
| Factorization of non-global LHC observables Part 1: Resummation of super-leading logarithms |
| Speaker: | Matthias Neubert (University of Mainz) |
| Abstract: | We present a systematic formalism based on a factorization theorem in Soft-Collinear Effective Theory (SCET) to describe non-global observables at hadron colliders, such as gap-between-jets cross sections. The cross sections are factorized into convolutions of hard functions, capturing the dependence on the partonic center-of-mass energy $\sqrt{\hat s}$, and low-energy matrix elements, which are sensitive to the low scale $Q_0\ll\sqrt{\hat s}$ characteristic of the veto imposed on energetic emissions into the gap region between the jets. The scale evolution of both objects is governed by a renormalization-group equation, whose form we derive. With the help of this equation, we develop an EFT-based approach to the resummation of so-called âÂÂnon-global logarithms'', including the âÂÂsuper-leading logarithmsâ discovered by Forshaw et al. in 2006, which only appear in hadron-collider processes. |
| Date: | Tue, 14.05.2024 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-Hoersaal, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, M. Procura |
| Exploring many-body problems with arrays of individual atoms |
| Speaker: | Antoine Browaeys (Institute d'Optique, Palaiseau ) |
| Abstract: | Over the last twenty years, physicists have learned to manipulate individual quantum objects: atoms, ions, molecules, quantum circuits, electronic spins... It is now possible to build "atom by atom" a synthetic quantum matter. By controlling the interactions between atoms, one can study the properties of these elementary many-body systems: quantum magnetism, transport of excitations, superconductivity... and thus understand more deeply the N-body problem. More recently, it was realized that these quantum machines may find applications in the industry, such as finding the solution of combinatorial optimization problems.
This seminar will present an example of a synthetic quantum system, based on laser-cooled ensembles of individual atoms trapped in microscopic optical tweezer arrays. By exciting the atoms into Rydberg states, we make them interact, even at distances of more than ten mic |
| Date: | Fri, 17.05.2024 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | Julian Leonard |
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