|
Calendar of Physics Talks Vienna
| Low-loss fluorescence detection of ytterbium atom arrays at the microsecond scale |
| Speaker: | Matteo Marinelli (University Trieste) |
| Abstract: | Scalable quantum technologies based on neutral atoms require fast, high-fidelity, and low-loss imaging of individual atoms. In this talk, I will present our recent results on achieving such imaging in optical tweezers without active cooling, enabled by the favorable atomic properties of ytterbium. Using a pulsed excitation scheme, we collect fluorescence on microsecond timescales, reaching single-atom discrimination fidelities above 99.9% and survival probabilities above 99.5% in a single shot. By interleaving short recooling pulses—just a few hundred microseconds for atoms in magic traps—we perform tens of consecutive detections with constant per-image loss. This capability is key for mid-circuit feedback in tweezer-based quantum processors and optical clocks. Unlike conventional protocols, our imaging does not induce parity projection in multiply-occupied traps. This allows number-reso |
| Date: | Mon, 07.07.2025 |
| Time: | 11:00 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | Julian Léonard |
| Quantum non-Gaussianity from Nonlinearity |
| Speaker: | Radim Filip (Palacky University) |
| Abstract: | Quantum non-Gaussian coherences are crucial for quantum technology involving bosonic systems, with validated applications in sensing and error correction. The talk will examine recent theoretical and experimental techniques that have enhanced our understanding, control, and use of quantum non-Gaussian coherences across optical, microwave, and mechanical platforms, stemming from genuine quantum nonlinearity in oscillator dynamics. This field remains challenging to explore both theoretically and experimentally. We will highlight recent achievements in contrast to ongoing problems. The talk will end with a review of future challenges in theory and experiment, focusing on genuine quantum nonlinear interactions with light, atoms, mechanical oscillators, and superconducting circuits, to promote discussion and further development of this promising area. |
| Date: | Tue, 08.07.2025 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Seminar room ZE 01-1, ATI |
| Contact: | Uros Delic |
| A Matrix Model Proposal for Quantum Gravity and the Quantum Mechanics of Black Holes |
| Speaker: | Chong-Sun Chu (Tsing-Hua University Taiwan) |
| Abstract: | We propose a quantum mechanical theory of quantum spaces described by large N non-commutative geometry as a model for quantum gravity.The model admits fuzzy sphere as solution whose energy-radius relation precisely matches with that of the Schwarzschild black hole. Moreover the fuzzy sphere is endrosed with a Fermi sea of states arising from quantizing the fermions over the fuzzy sphere background. The counting of these microstates reproduces precisely the Bekerstein-Hawking entropy of black hole. We also show that the solution is stable against energy preserving perturbations, exactly like that of the Schwarzschild black hole in General Relativity. A more nontrival check is provided by the rotating fuzzy sphere solution, which we show to reproduce the energy, size, shape, angular momentum and entropy of the Kerr black hole in General Relativity. We will discuss how Newtonian gravity may |
| Date: | Thu, 10.07.2025 |
| Time: | 13:15 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-HS, Boltzmanngasse 5, 1090 Wien, 5.Stock |
| Contact: | S. Fredenhagen, M. Sperling |
| Enhancing Quantum Sensors for Space Applications using Entanglement |
| Speaker: | Simon Haase (Universität Hamburg) |
| Abstract: | Atom interferometers are high-precision sensors for acceleration, rotation and magnetic fields. Space-borne atom interferometers promise a wide range of applications from geodesy to fundamental tests of physics. Their improved sensitivity due to prolonged interrogation times benefits from the macroscopic coherence length and slow expansion rates of Bose-Einstein condensates (BECs). A limit for the precision is the Standard Quantum Limit. By using entangled ensembles of atoms, the limit can be surpassed, improving the sensitivity of interferometric measurements.
The INTENTAS project is designed as a source of entangled atoms that can be operated on a microgravity platform. To demonstrate sensitivity beyond the Standard Quantum Limit, a rubidium BEC is generated, entangled via spin-changing collisions and detected with high resolution. In this talk I will present an overview of the experi |
| Date: | Thu, 10.07.2025 |
| Time: | 15:30 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | Julian Léonard |
|