ERIK MCLEAN / UNSPLASH

Physikalisches Kolloquium

Freitag, 11. Juli 2025 17:00 Uhr  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.

Teilchenkolloquium

Astronomisches Kolloquium

Dienstag, 8. Juli 2025 16:30 Uhr  Compact star mergers, kilonovae and r-process element production

Stephen Smartt , University of Oxford Two binary neutron star mergers have been detected from their gravitational wave signature. The first, in 2017 had an electromagnetic counterpart comprising a high energy and radio emission and a thermal component called a kilonova powered by radioactive heavy elements. The composition of the ejecta, mostly elements heavier than iron is still debated. Nucleosynthesis and atomic data arguments suggest a number of 1st and 2nd process elements have detected spectral signatures. The was no counterpart from the second binary neutron star merger in 2019 and no further merger has been detected by LIGO-Virgo-Kagra since. However, surprisingly two long gamma ray bursts have shown convincing signatures of an infra-red excess powered by heavy element decay, and the luminosity can be modelled with kilonova thermal emission. I will present the data, current debates on the chemical element signatures in the spectrum, discuss the relatively low rate of discovery and the put the two long GRB discoveries into context. To arrange a visit with the speaker during the visit, please contact their host: Fabian Schneider

Zentrum für Quantendynamik Kolloquium

Mittwoch, 9. Juli 2025 17:00 Uhr  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.