Programm Sommersemester 2022

Mo, 11.07.2022, 16:15 Uhr Physik Hörsaal, 28 D 001

Constantin Häfner (Fraunhofer Institute for Laser Technology, Aachen)

On the cusp of fusion energy



Nuclear fusion has, in principle, a high potential for sustainable energy production. In contrast to fission, in which heavy nuclei such as uranium are split under neutron bombardment, nuclear fusion involves fusing light nuclei to extract the binding energy. After decades of inertial confinement fusion research, a record yield of more than 1.3 megajoules was achieved in the laboratory for the first time on August 8, 2021, in an experiment at Lawrence Livermore National Laboratory's National Ignition Facility. This result demonstrated exceeding the Lawson criterion. It has retriggered interest in fusion energy as a path to clean energy and energy security, with over $4B private investments. This talk will review the experimental results and technologies that made this breakthrough possible, and the implications for future research.


Host:  Thomas Taubner




Mo, 13.06.2022, 16:15 Physik Hörsaal, 28 D 001

Alfons Weber (Mainz University)

Neutrinos Oscillations - Physics Beyond the Standard Model



Neutrinos are the most abandon matter particle in the universe, but very little is known about them. Originally proposed by Pauli as an undetectable placeholder to save energy- and angular momentum conservation, they have come a long way and surprising us at every step. It is now known that neutrinos have mass and that the mass- and interaction-eigenstates are not the same, which leads to a phenomenon called neutrino oscillations. The colloquium will report on the current knowledge on the field concentrating on accelerator based experiments and highlight future facilities, which will make precision experiments and might tell us, if neutrinos and anti-neutrinos behave the same or not. Differences between neutrinos and anti-neutrinos (CP-violation) may shed some light why our universe is matter dominated.


Host: Achim Stahl und Stefan Roth




Mo, 30.05.2022, 16:15 Physik Hörsaal, 28 D 001

Jonathan Home (ETH Zurich)

The quest to scale ion trap quantum computers



Trapped-ions are among the leading platforms for realising large-scale quantum computers, offering excellent coherence as well as demonstrations of the highest fidelity quantum logic gates. However many challenges, both technical and scientific remain in scaling these systems to relevant sizes for performing useful algorithms. I will give an overview of our work in both of these areas. On the technical side, this includes the integration of photonics on the chips used to trap ions, simplifying the delivery of light. Scientifically, we have explored new ways of realising quantum error correction with ions, which has enabled us to demonstrate using hundreds of rounds of correction that the coherence of a logical qubit can be extended by a factor of more than 3.


Host: Markus Müller




Mo, 16.05.2022, 16:15 Physik Hörsaal, 28 D 001

Stefan Hecht (Leibniz Institute for Interactive Materials, Aachen)

Enlightening Materials, Devices, and Manufacturing



Using an external light stimulus to control and power advanced materials and devices thereof in a dynamic fashion with superior spatial and temporal resolution offers tremendous opportunities. In this context, molecular photoswitches that undergo reversible changes upon illumination have become key ingredients. To develop these systems into high-performing materials and practical applications the switching processes have to be highly efficient and reliable. Both criteria are stringent and necessitate continuing optimization of key parameters, involving spectral separation and selective addressability, high quantum yields, and enhanced (photo)chemical resistance enabling highly repetitive switching without fatigue. Importantly, the photoswitchable systems have to undergo significant changes of a physicochemical property to maximize the overall achievable modulation. This presentation will highlight selected examples from our laboratory to illustrate how progress in molecular design can be translated into material, device, and manufacturing innovation.


Host: Carsten Honerkamp