|
Calendar of Physics Talks Vienna
| Computational Solutions to the Many-Body Schrödinger Equation Using High-Performance Computing (Vienna Theory Lunch Seminar) |
| Speaker: | Andreas Irmler (TU Wien ) |
| Abstract: | Despite being studied for over a decade solving the electronic Schroedinger equation exactly for systems with more than a few electrons remains a significant challenge. In this presentation, I will discuss why obtaining sufficiently accurate solutions is inherently complex and why such solutions are still urgently needed. To address this, I will introduce the Coupled Cluster method, a powerful approach that reformulates the problem into an algebraic framework. Additionally, I will demonstrate how the resulting equations can be efficiently solved using supercomputing techniques.
[[part of the "Vienna Theory Lunch Seminar, see https://lunch-seminar.univie.ac.at ]] |
| Date: | Tue, 22.10.2024 |
| Time: | 12:30 |
| Duration: | 75 min |
| Location: | TU Wien: Wiedner Hauptstr. 8-10, yellow area, 10th floor, seminar room DB10E11 |
| Contact: | Florian Lindenbauer |
| Mirror Symmetry and the Dualization Algorithm |
| Speaker: | Fabio Marino (University of Vienna) |
| Abstract: | Mirror symmetry is an IR duality enjoyed by some supersymmetric QFTs realized in type IIB superstring theory and, as such, it is usually presented at the branes level. However, there is a procedure known as the âdualization algorithmâ which allows us to implement mirror symmetry directly at the QFT level.
In this talk I will try to illustrate where does this technique come from, how does it work and which are the outstanding results it can provide. In particular, I will first put it to work on the simple example provided by good SQCD, in order to get some intuition, and then to the quite intricate case of the so called âbadâ SQCD.
Here we will se arising a very interesting feature: bad theories have a partition function which behaves as a sum of distribution rather than a regular function of the deformation parameters. |
| Date: | Tue, 22.10.2024 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-Hoersaal, 1090 Vienna, Boltzmanngasse 5, 5th floor |
| Contact: | S. Fredenhagen, M. Sperling |
| Factorization restoration through Glauber gluons, Part 1 |
| Speaker: | Matthias Neubert (University of Mainz) |
| Abstract: | I will discuss new insights into the low-energy dynamics of gap-between-jets cross sections at hadron colliders, for which phase factors in the hard amplitudes spoil collinear cancellations and lead to double (âsuper- leadingâ) logarithmic behavior. Based on a method-of-regions analysis, we have identified three-loop contributions from perturbative active-active Glauber-gluon exchanges with the right structure to render the cross section consistent with PDF factorization below the gap veto scale. These Glauber contributions are unambiguously defined without regulators beyond dimensional regularization. |
| Date: | Tue, 22.10.2024 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | A. Hoang, M. Procura |
| Direct extraction of path weak values from interferograms without auxiliary qubit |
| Speaker: | Ismaele Vincent Masiello (TU Wien, Atominstitut) |
| Abstract: | Since the first definition by Y. Aharonov, D. Albert, and L. Vaidman, weak values have gained an important role in the field of quantum physics. In particular, they have been shown to be strictly related to many fundamental concepts of quantum mechanics, such as: uncertainty relations, negative quasi-probability distributions, quantum paradoxes, and more. Neutron interferometry has historically been a pillar in studying the foundations of quantum phenomena, and once more revealed itself to be a valuable tool for the study of weak values.
The 2 paths of an interferometer constitute a two-level quantum system: it is in all regards a qubit. Moreover, the established quantum nature of neutrons, which enter the interferometer one particle at a time, doesnât leave space to any other classical interpretation of the phenomena. Weak values of the path operators have been extracted by using an an |
| Date: | Wed, 23.10.2024 |
| Time: | 16:15 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | Maximilian Prüfer |
| Erwin Schrödinger Lecture: Ice clouds over the Asian monsoon and their role in the global climate |
| Speaker: | Martina Krämer (University of Mainz) |
| Abstract: | The Asian Summer Monsoon is the most pronounced atmospheric weather system during boreal summer, consisting of a large-scale anticyclone extending from Asia to the Middle East. Moist air masses are transported via strong convection or general tropical upwelling to altitudes where the coldest temperatures in the atmosphere are found.
The ice clouds over the Asian monsoon can have either a warming or a cooling effect. Also, they affect the amount of water vapour in the tropical upper troposphere, from where the water vapour is further transported into the stratosphere as far as the Arctic Circle. Because water vapour is a strong greenhouse gas, it causes a warming directly in the tropics up to the Arctic stratosphere.
Understanding the overall effect of ice clouds on this chain of processes is a focus of recent research. |
| Date: | Wed, 23.10.2024 |
| Time: | 17:00 |
| Duration: | 60 min |
| Location: | Erwin Schrödinger Institute, U of Vienna, Boltzmanngasse 9, Boltzmann Lecture Hall |
| Contact: | Erwin Schrödinger Institute, secr@esi.ac.at |
| Erasure detection with superconducting qubits |
| Speaker: | Alex Retzker (Hebrew University Jerusalem) |
| Abstract: | The amplitude damping time, T1, has long stood as the major factor limiting quantum fidelity in superconducting circuits, prompting concerted efforts in the material science and design of qubits aimed at increasing T1. In contrast, the dephasing time, TÏ, can usually be extended above T1 (via, e.g., dynamical decoupling), to the point where it does not limit fidelity. In this talk I will describe a proposal[1] and its implementation[2] of a scheme for overcoming the conventional T1 limit on fidelity by designing qubits in a way that amplitude damping errors can be detected and converted into erasure errors via a dual rail construction.
We experimentally demonstrated that a "dual-rail qubit" consisting of a pair of resonantly-coupled transmons can form a highly coherent erasure qubit, where the erasure error rate is given by the transmon T1 but for which residual dephasing is strongly sup |
| Date: | Fri, 25.10.2024 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Helmut Rauch Lecture Hall |
| Contact: | Tomas Sikorsky |
|