Hauptinhalt
Gemeinsames Kolloquium des
Fachbereichs Physik und des SFB 1083
Wintersemester 2023/24
mittwochs 15:30 Uhr
Renthof 5, Großer Hörsaal
08.11.2023 Per Delsing, Chalmers University of Technology
Superconducting Circuits, from Artificial Atoms to Quantum Computers
Abstract:
In this talk I will describe how superconducting circuits can be used both as superconducting qubits and as artificial atoms.
The first part of the talk describes the quantum technology center in Sweden, our effort to make high quality qubits and how they are integrated to make a quantum processor. The second part of the talk describes how superconducting qubits can be used as artificial atom and how exotic regimes can be reached to study interesting physics. In particular I will discuss how they can be used to generate nonclassical states of microwaves, and how the can be engineered to couple to sound rather than to light.15.11.2023 Carsten Weber, Carl Zeiss AG
Hunting the Picometer - Most Accurate Mirrors of the World
Abstract:
The demand for smaller and more energy-efficient microchips is key for numerous technological advancements, from fast communication to autonomous driving. To support this thirst for chips and to continue Moore's law, the ground-breaking developments of ZEISS optics play a key role. In this talk, an overview over the different generations of lithography optics of ZEISS is given. Applications and current developments are discussed. Insights into the challenges in production and operation of optics for extreme ultraviolet (EUV) radiation are presented.22.11.2023 Annette Köhler, Universität Bayreuth
Organic Electronic Materials for Today and Tomorrow
Abstract:
Organic semiconductors are well established in present-day applications such as mobile phone or TV displays or photocopiers. Interest into their photophysics is currently rekindled by solar cell efficiencies exceeding 19% as well as by emerging applications in the area of bioelectronics. In this talk I want to highlight what makes these materials so special and why their photophysics differs from that of conventional inorganic semiconductors.13.12.2023 Stefan Mathias, Universität Göttingen
Excitonics at the Space-Time Limit
Abstract:
In 2D semiconducting quantum materials, organic semiconductors and their heterostructures, the energy of absorbed light is stored in Coulomb-bound electron-hole pairs, which are called excitons. For future technological applications of these classes of materials, for instance in optoelectronics and for energy harvesting, it is crucial to study the initial exciton formation and also the subsequent relaxation and dissipation processes at the fundamental level and on the relevant length and time scales.
In our research, we have built a new photoemission-based experiment [1] that is capable of studying excitonics at the space-time limit corresponding to nanometers and femtoseconds. In a series of experiments, we identified characteristic signatures in the exciton formation process and the pathways of subsequent energy conversion and thermalization. In addition, the new experiment gives us access to the so-called “dark exciton landscape”, where we can follow exciton dynamics with unprecedented temporal and spatial resolution.
In my talk, I will present the ultrafast formation dynamics of dark interlayer excitons in twisted WSe2/MoS2 heterostructures. In particular, I will report on the identification of a key signature of the moiré superlattice that is imprinted on the momentum-resolved interlayer exciton photoemission signal [2]. Furthermore, I will present photoemission exciton tomography [3] that allows us to disentangle multiorbital contributions in the exciton formation of the organic semiconductor buckminsterfullerene C_60.References
[1] Keunecke et al., Rev. Sci. Ins. 91, 063905 (2020).
[2] Schmitt et al., Nature 608, 499 (2022).
[3] Bennecke et al., arXiv:2305.18908 (2023).17.01.2024 Paul Erhart, Chalmers University of Technology
From Atomic Scale Modeling via Machine Learning to Experiments
31.01.2024 Alexander Föhlisch, Universität Potsdam und Helmholtz Zentrum Potsdam
Synchrotron Radiation as a Modern Tool in Materials Science
14.02.2024 Bernadette Kunert, IMEC Leuven
Towards 6G Communication Networks