Browsing Fakultät für Physik (inkl. GAUSS) by Referee "Ropers, Claus Prof. Dr."
Now showing items 1-20 of 30
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Radio-frequency controlled low-energy electron pulses
(2024-08-23)Electron beams are invaluable for probing material structures and dynamic processes due to their large scattering cross sections and the versatility of tunable electron optics for diffraction and microscopy. Pulsed electron ... -
Ultrafast spin dynamics in FeNi alloys
(2023-11-17)In this thesis, the optical intersite spin transfer in ferromagnetic FeNi alloys is studied on the femtosecond timescale. Extreme ultraviolet transverse magneto-optical Kerr effect spectroscopy (EUV T-MOKE) is used to ... -
Symmetries and correlations in solids probed by ultrafast high-harmonic spectroscopy
(2023-11-13)Novel material systems with correlated and tunable properties promise to push the boundaries of current information processing and energy management technologies. Their investigation requires simultaneous access to multiple ... -
Correlated phases in the vicinity of tunable van Hove singularities in Bernal bilayer graphene
(2023-08-18)The naturally occurring Bernal bilayer graphene exhibits a complex low-energy band structure hosting electric-field-controlled Lifshitz transitions and van Hove singularities. The diverging density of states is predicted ... -
Imaging vortex pinning and gyration by time-resolved and in-situ Lorentz microscopy
(2023-03-08)Magnetism encompasses a large variety of scientifically interesting and industrially valuable phenomena. In particular, nanoscopic magnetic textures—such as vortices, merons and skyrmions—have been in the spotlight of ... -
STED microscopy with two-photon photoactivation in the visible range & Application of generative adversarial networks for image reconstruction in STED microscopy
(2023-01-31)The resolution limit of classical optical far-field microscopes was broken with the invention of super-resolution microscopy. Today, a variety of these techniques achieving different degrees of resolution exist. Image formation ... -
Local excitation of confined molecule-surface hybrid systems
(2022-11-28)Molecule-surface hybrid systems promise solutions for a variety of technological challenges – including the development of efficient catalysts as well as of molecular electronic devices. In this work, different molecule ... -
A matter of brightness: table-top X-ray generation inside waveguides and X-ray holography with single free-electron laser pulses
(2022-03-22)X-ray microscopy delivers insights into the structure of optically opaque bulk specimens with high spatial resolution. The source brightness poses a limit on the achievable resolution, however. While table-top X-ray sources ... -
Laser Frequency Combs for High Resolution Spectrograph Calibration
(2021-10-28)While laser frequency combs (LFCs) are in principle ideal calibration light sources for high resolution spectrographs, they are still not regularly used. This is not only due to high cost and maintenance, but also persistent ... -
Ultrafast Probing and Coherent Vibrational Control of a Surface Structural Phase Transition
(2021-08-26)The present thesis explores the coherent control of surface structural phase transitions by all-optical manipulation of key vibrational modes. To this end, ultrafast low-energy electron diffraction (ULEED) in combination ... -
Ultrafast transmission electron microscopy of a structural phase transition
(2021-08-09)High hopes are placed on materials with tunable properties and excitations for future applications in energy conversion devices. Functionality of devices, however, not only arises from the properties of individual materials ... -
Ultrafast electron dynamics measured with a novel time-resolved high-repetition rate momentum microscopy setup
(2021-03-25)In this thesis, a new generation of a trARPES experiment has been successfully built up from scratch combining the advantages of a ToF momentum microscope with a lab-based HHG source, delivering femtosecond EUV pulses, ... -
Probing Light-Matter Interactions in Plasmonic Nanotips
(2020-09-03)The exploration of light-matter interaction has inspired some of the most essential theories and applications in fundamental science and technology. Cutting-edge research, such as ultrafast time-resolved and super-resolution ... -
Non-equilibrium structural Dynamics of incommensurate Charge-Density Waves
(2020-07-01)In recent years, charge-density wave (CDW) systems have been studied extensively, as they provide a diverse testing field for basic concepts in electron-phonon coupling, electron correlation, and structural phase transitions. ... -
Polaronic behaviour at manganite interfaces studied by advanced Raman scattering techniques
(2020-03-20)This work focusses on the polaronic behaviour at manganite interfaces studied by various Raman spectroscopy techniques. Temperature- and magnetic-field-dependent studies probe the polaronic behaviour at the internal ... -
Quantum Sensing with NV Centers in Diamond
(2019-10-22)This thesis is concerned with studies involving quantum sensing based on Nitrogen-Vacancy (NV) center in diamond. Essentially, it attempts to address two important problems. First, enhancing the sensitivity of a single ... -
Ultrafast Lorentz Microscopy using High-Coherence Electron Pulses
(2019-05-08)Information processing and storage applications demand increasing miniaturization and operation speeds, where optical manipulation of magnetic order may play a very important role. It is hence essential to study how light ... -
Modeling electrodynamics in the vicinity of metal nanostructures
(2019-03-08)In this work, we show how a profound theoretical understanding of a seemingly exotic phenomenon, namely the influence of metal structures on fluorescence lifetimes, has lead to the development of a microscopy technique ... -
Ultrafast low-energy electron diffraction at surfaces
(2019-02-22)Due to their reduced dimensionality, surfaces and quasi two-dimensional materials exhibit numerous intriguing physical phenomena that drastically differ from the bulk. To resolve these effects and the associated dynamics ... -
Hochauflösende Bildgebung und NEXAFS-Spektroskopie mit weicher Röntgenstrahlung aus laserinduzierten Plasmen
(2019-01-24)Soft x-ray microscopy and absorption spectroscopy are extremely useful tools for high-resolution imaging and chemical analysis of samples in various scientific fields. However, due to the required high photon flux of ...