ERIK MCLEAN / UNSPLASH

Physikalisches Kolloquium

Friday, 11. July 2025 5:00 pm  Advancing Quantum Information Processing with Superconducting Circuits

Prof. Dr. Stefan Filipp, Walther-Meißner-Institut und TU München Quantum computers have the potential to solve complex problems efficiently. However, to unleash their full potential, complex quantum systems have to be manufactured, manipulated and measured with unprecedented accuracy and precision. In this presentation I will focus on superconducting qubits as one of the most promising platforms for quantum computing. I will illustrate the building blocks of a quantum processor using a system based on 17 transmon-type qubits, which we are currently operating in our laboratory. In this architecture tunable coupling elements are harnessed to generate multi-qubit operations between two or more qubits and to efficiently create many-body entanglement. Moreover, I will address alternative superconducting qubits with improved protection against environmental influences.

Particle Colloquium

The LHCb Phase-2b upgrade

Prof. Dr. Ulrich Uwer, Physikalisches Institut, Universität Heidelberg

Astronomy colloquium

Tuesday, 15. July 2025 4:30 pm  From mass transfer to stripped stars

Pablo Marchant, Ghent University Binary interactions shape the evolution of the most massive stars, leading to significant deviations from the evolutionary pathways possible in single star evolution. These processes impact the universe at large scales and result in high energy events such as peculiar supernovae and gravitational wave sources. To understand these outcomes, it is important to assess binary evolution in early stages ranging from pre-interaction, roche-lobe overflow and post-interaction phases. I will discuss the current progress in our understanding of mass-transferring binaries, covering the impact of this process on the donor star (with the possible production of a stripped star), as well as the response of its companion. Of particular importance in recent years is the identification of bloated stripped stars caught immediately after interaction which provides a snapshot of the end-states of mass transfer, and I will discuss how their properties constrain orbital evolution and the efficiency of mass transfer. I will also emphasize that many of the uncertain processes in massive binary star evolution can also be assessed through the study of intermediate mass systems, for which the physics in early evolutionary phases does not differ significantly. To arrange a visit with the speaker during the visit, please contact their host: Jaime Villaseñor (MPIA)

Center for Quantum Dynamics Colloquium

Wednesday, 9. July 2025 5:00 pm  Exploring quantum Hall physics with ultracold dysprosium atoms

Prof. Sylvain Nascimbene, Département de Physique, École normale superérieure, Paris Exploring quantum Hall physics with ultracold dysprosium atoms Prof. Sylvain Nascimbène Laboratoire Kastler Brossel, Collège de France, Paris Ultracold atomic gases offer a versatile platform for exploring rich phenomena in quantum matter. In particular, topological states akin to those found in the quantum Hall effect can be engineered by simulating orbital magnetic fields—an approach greatly facilitated by the use of synthetic dimensions. In this talk, I will present our experimental realization of a quantum Hall system using ultracold gases of dysprosium atoms. By leveraging the atom’s large internal spin (J=8), we encode a synthetic dimension and couple it to atomic motion via two-photon optical transitions, which generates an effective magnetic field. We observe hallmark signatures of quantum Hall physics, including a quantized Hall response and gapless, chiral edge modes. I will then describe a more intricate experiment designed to probe spatial entanglement by simulating the so-called entanglement Hamiltonian. Using the Bisognano-Wichmann theorem—which relates the entanglement Hamiltonian to a spatially deformed version of the original system—we implement this deformation along the synthetic dimension. Lastly, I will discuss our recent investigation into a topological phase transition, induced by introducing an additional lattice potential. I will highlight the system’s behavior in the critical regime and explore the emergent features associated with the transition.