Browsing Fakultät für Physik (inkl. GAUSS) by Referee "Mathias, Stefan Prof. Dr."
Now showing items 1-20 of 27
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Capturing exciton wavefunctions by time-resolved photoemission orbital tomography
(2025-11-05)Excitons are realizations of a correlated many-body wavefunction, consisting of a Coulomb-bound electron and hole pair. They are the dominant excitations in semiconducting organic and low-dimensional quantum materials and ... -
Observation of Floquet states in graphene
(2025-09-17)Recent advances in the field of condensed-matter physics have unlocked the potential to realize and control emergent material phases that are not accessible in thermal equilibrium. One of the most promising concepts in ... -
Ultrafast exciton dynamics in moiré heterostructures
(2025-08-05)The optoelectronic properties of two-dimensional semiconductors are defined by two-particle correlated exciton states formed via the Coulomb interaction between single-particle holes and electrons. After excitation with ... -
Development and Characterization of a Pump-Probe Setup for Broadband Time-Resolved Reflectivity Measurements with Sub-10 Femtosecond Resolution
(2025-07-21)It has long been known that light as a tool can used for material modification. In order to explore the related possibilities for a wide range of materials in science and tech- nology, tremendous efforts has been made ... -
Quantification procedure of surface stress states and its application for measurements on glass using a reflection polarimeter
(2025-07-14)The investigation of surface stress of glass is highly requested for quality control processes, e.g. in the automotive glass industry. Since the state-of-art instruments are not really applicable to industrial processes ... -
Optical Creation and Control of Magnetic Spin Textures
(2025-07-04)Exploring the rich physics of magnetic spin textures, particularly topologically non-trivial magnetic skyrmions, opens a promising pathway for the development of novel spintronic and magnonic devices. This thesis investigates ... -
Operando and Ultrafast Electron Microscopy of Structural Phase Transformations
(2025-05-05)Structural phase transformations promise tailored functionality in future technological devices that complement already established applications. In leveraging the associated changes of macroscopic properties, reversible, ... -
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 momentum microscopy of dark exciton dynamics in real- and reciprocal-space
(2023-12-22)Combining both worlds of momentum and real-space time-resolved momentum microscopy, this thesis introduces a new approach to probe the entire exciton landscape and dynamics of twisted TMD heterostructures with momentum-, ... -
Unraveling Femtosecond Spin and Charge Dynamics with EUV T-MOKE Spectroscopy
(2023-12-15)In this thesis, a novel transverse magneto-optical Kerr effect (T-MOKE) setup with extreme ultraviolet light from high-harmonic generation between 30 and 72 eV is used to study the spectrally-resolved spin and charge ... -
Non-equilibrium Phases in Jahn-Teller-distorted Perovskite Manganites
(2023-12-04)Optical control of condensed matter, being inherently fast and energy efficient, sparks hope for potential technical applications. However, these require a fundamental understanding of the physical mechanisms behind. In ... -
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 ... -
Phase-Dependent Energy Dissipation Processes in La0.7Sr0.3MnO3 and (La0.6Pr0.4)0.7Ca0.3MnO3 after an Ultrashort Optical Excitation
(2023-08-31)La0.7Sr0.3MnO3 (LSMO) and (La0.6Pr0.4)0.7Ca0.3MnO3 (LPCMO) are perovsikte manganites which both show a ferromagnetic-to-paramagnetic phase transition. Interestingly, the development of the new phase when crossing the ... -
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 ... -
Far-from-Equilibrium Quasiparticle Dynamics in Graphene
(2023-01-17)Comprehending far-from-equilibrium many-body interactions is one of the major goals of current ultrafast condensed matter physics research. Here, a particularly interesting but barely understood situation occurs during a ... -
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 ... -
Combined Study of Local Spectroscopy and Macroscopic Electronic Transport of the Correlated Honeycomb Spin-Orbit Mott Insulator Na2IrO3
(2022-04-11)The search for novel phenomena that exceeds and interconnects our existing knowledge is at the heart of every scientific effort. Physics, and particularly solid-state research, is no exception. If anything, the ... -
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 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, ...