Browsing Fakultät für Physik (inkl. GAUSS) by Referee "Mathias, Stefan Prof. Dr."
Now showing items 1-19 of 19
-
Coherent Control and Reconstruction of Free-Electron Quantum States in Ultrafast Electron Microscopy
(2018-01-04)The present (cumulative) thesis examines the quantum coherent interaction of ultrashort free-electron pulses with tailored optical near-fields. Multiple fields are utilised to prepare, coherently manipulate and characterise ... -
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 ... -
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 ... -
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 ... -
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 ... -
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 ... -
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. ... -
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 ... -
Scanning Tunneling Spectroscopy of Rare Earth Hexaborides
(2020-12-22)Rare earth hexaborides are a well-suited model system for the exploration of correlation physics. The varying 4f occupation of the rare earth elements result in a richness of correlated electron phenomena, which harbor ... -
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 ... -
Thermalization in one-dimensional quantum-many-body systems
(2017-01-16)We consider the thermalization of the momentum distribution in two one-dimensional models. The first one is the integrable Hubbard model with an additional integrability breaking term in the Hamiltonian, which is a ... -
THz streaking at metal nanotips
(2018-03-20)This thesis addresses various aspects of terahertz (THz) streaking at metallic nanotips. In THz near-field streaking, electron pulses emitted by femtosecond near-infrared (NIR) pulses are accelerated in a THz-induced ... -
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, ... -
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 ... -
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 ... -
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-, ... -
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 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 ... -
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 ...