B. Rethfeld
YOU?
Author Swipe
View article: Collapse of electron–phonon coupling due to nonthermal phonon populations
Collapse of electron–phonon coupling due to nonthermal phonon populations Open
Electron–phonon coupling governs the energy transfer rate between electrons and the crystal lattice. It is of crucial importance to the relaxation dynamics of laser-excited solids, as only the electron system can be directly excited by opt…
View article: Intrinsically energy-dependent spin dynamics in ultrafast demagnetization
Intrinsically energy-dependent spin dynamics in ultrafast demagnetization Open
Ultrafast magnetization dynamics has the potential to spark a new era of information technology by harnessing the interaction between spin and light. Recent studies indicate a complex interplay between the microscopic spin and band structu…
View article: Femtosecond versus nanosecond magnetization dynamics in ultrathin ferromagnetic bilayers
Femtosecond versus nanosecond magnetization dynamics in ultrathin ferromagnetic bilayers Open
We investigate the magnetization dynamics of an ultrathin Co (1.5 nm)/Py (1.5 nm) bilayer system from femtosecond (fs) to nanosecond (ns) timescales. Magnetization dynamics in the fs timescales is characterized as a highly nonequilibrium r…
View article: Probing laser-driven surface and subsurface dynamics via grazing-incidence XFEL scattering and diffraction
Probing laser-driven surface and subsurface dynamics via grazing-incidence XFEL scattering and diffraction Open
We demonstrate a grazing-incidence x-ray platform that simultaneously records time-resolved grazing-incidence small-angle x-ray scattering (GISAXS) and grazing-incidence x-ray diffraction (GID) from a femtosecond laser-irradiated gold film…
View article: Capturing non-equilibrium electron dynamics in metals accurately and efficiently
Capturing non-equilibrium electron dynamics in metals accurately and efficiently Open
The simulation of non-equilibrium electron distributions is essential for capturing light–metal interactions and therefore the study of photoabsorption, photocatalysis, laser ablation, and many other phenomena. Current methodologies, such …
View article: Influence of phonon stiffness on electron–phonon energy transfer
Influence of phonon stiffness on electron–phonon energy transfer Open
Electron–phonon coupling plays a crucial role in describing the energy relaxation dynamics of solids excited by ultrafast laser pulses. It depends on electronic and phononic properties to varying degrees for different metals. In many studi…
View article: Signatures of ballistic and diffusive transport in the time-dependent Kerr-response of magnetic materials
Signatures of ballistic and diffusive transport in the time-dependent Kerr-response of magnetic materials Open
We calculate the influence of diffusive and ballistic transport on ultrafast magnetization in thick metallic films. When only diffusive transport is present, gradients of magnetization in the material remain up to picosecond timescales. In…
View article: Dynamic interfacial effects in ultrathin ferromagnetic bilayers
Dynamic interfacial effects in ultrathin ferromagnetic bilayers Open
We investigate the magnetization dynamics of an ultrathin Co (1.5 nm) /Py (1.5 nm) bilayer system from femtosecond (fs) to nanosecond (ns) timescales. Magnetization dynamics in the fs timescales is characterized as a highly non-equilibrium…
View article: Roadmap for warm dense matter physics
Roadmap for warm dense matter physics Open
This roadmap presents the state-of-the-art, current challenges and near future developments anticipated in the thriving field of warm dense matter physics. Originating from strongly coupled plasma physics, high pressure physics and high en…
View article: Ultrafast electron-phonon scattering in an antiferromagnetic Dirac semimetal
Ultrafast electron-phonon scattering in an antiferromagnetic Dirac semimetal Open
Topological antiferromagnetic systems, which exhibit anisotropic band structures combined with complex relativistic spin structures in momentum space, have shown strong magnetoresistance effects driven by Dirac fermion characteristics. Whi…
View article: Capturing non-equilibrium electron dynamics in metals accurately and efficiently
Capturing non-equilibrium electron dynamics in metals accurately and efficiently Open
The simulation of non-equilibrium electron distributions is essential for capturing light-metal interactions and therefore the study of photoabsorption, photocatalysis, laser ablation, and many other phenomena. Current methodologies, such …
View article: Influence of band occupation on electron-phonon coupling in gold
Influence of band occupation on electron-phonon coupling in gold Open
Electron-phonon coupling is a fundamental process that governs the energy relaxation dynamics of solids excited by ultrafast laser pulses. It has been found to strongly depend on the electron temperature as well as on nonequilibrium effect…
View article: Stable optical response during electron–phonon equilibration in laser-excited gold
Stable optical response during electron–phonon equilibration in laser-excited gold Open
We study the optical response of solid gold driven by ultrashort pulses of visible light by tracking the conduction band density and damping rates. While we find rapid changes in optical properties during and shortly after the laser excita…
View article: Signatures of ballistic and diffusive transport in the time-dependent Kerr-response of magnetic materials
Signatures of ballistic and diffusive transport in the time-dependent Kerr-response of magnetic materials Open
We calculate the influence of diffusive and ballistic transport on ultrafast magnetization in thick metallic films. When only diffusive transport is present, gradients of magnetization in the material remain up to picosecond timescales. In…
View article: Influence of band occupation on electron-phonon coupling in gold
Influence of band occupation on electron-phonon coupling in gold Open
Electron-phonon coupling is a fundamental process that governs the energy relaxation dynamics of solids excited by ultrafast laser pulses. It has been found to strongly depend on electron temperature as well as on nonequilibrium effects. R…
View article: Effect of iron thicknesses on spin transport in a Fe/Au bilayer system
Effect of iron thicknesses on spin transport in a Fe/Au bilayer system Open
This paper is concerned with a theoretical analysis of the behavior of optically excited spin currents in bilayer and multilayer systems of ferromagnetic and normal metals. As the propagation, control, and manipulation of the spin currents…
View article: An adaptive model for the optical properties of excited gold
An adaptive model for the optical properties of excited gold Open
We study the temperature-dependent optical properties of gold over a broad energy spectrum covering photon energies below and above the interband threshold. We apply a semi-analytical Drude-Lorentz model with temperature-dependent oscillat…
View article: Time-resolved spectral densities of non-thermal electrons in gold
Time-resolved spectral densities of non-thermal electrons in gold Open
Noble-metal nanoparticles for photocatalysis have become a major research object in recent years due to their plasmon-enhanced strong light-matter interaction. The dynamics of the hot electrons in the noble metal are crucial for the effici…
View article: Ultrafast electron-phonon scattering in antiferromagnetic Dirac semimetals
Ultrafast electron-phonon scattering in antiferromagnetic Dirac semimetals Open
Topological antiferromagnetic systems, which exhibit anisotropic band structures combined with complex relativistic spin structures in momentum space, have shown strong magnetoresistance effects driven by Dirac fermion characteristics. Whi…
View article: Competing signatures of intersite and interlayer spin transfer in the ultrafast magnetization dynamics
Competing signatures of intersite and interlayer spin transfer in the ultrafast magnetization dynamics Open
Optically driven intersite and interlayer spin transfer are individually known as the fastest processes for manipulating the spin order of magnetic materials on the sub 100 fs time scale. However, their competing influence on the ultrafast…
View article: Interplay of electron-magnon scattering and spin-orbit induced electronic spin-flip scattering in a two-band Stoner model
Interplay of electron-magnon scattering and spin-orbit induced electronic spin-flip scattering in a two-band Stoner model Open
This paper presents a theoretical investigation of the influence of electron-magnon scattering processes on the ultrafast demagnetization in itinerant ferromagnets. In the framework of a ferromagnetic model system, we compute the spin-depe…
View article: Intertwined relaxation processes maintain athermal electron distribution in laser-excited dielectrics
Intertwined relaxation processes maintain athermal electron distribution in laser-excited dielectrics Open
We study the relaxation dynamics of laser-excited non-equilibrium electron distributions in the valence- and conduction band of a dielectric. We apply Boltzmann collision integrals to trace the influence of different scattering mechanisms …
View article: Laser‐Induced Creation of Antiferromagnetic 180‐Degree Domains in NiO/Pt Bilayers
Laser‐Induced Creation of Antiferromagnetic 180‐Degree Domains in NiO/Pt Bilayers Open
The antiferromagnetic order in heterostructures of NiO/Pt thin films can be modified by optical pulses. After the irradiation with laser light, the optically induced creation of antiferromagnetic domains can be observed by imaging the crea…
View article: Effect of iron thicknesses on spin transport in a Fe/Au bilayer system
Effect of iron thicknesses on spin transport in a Fe/Au bilayer system Open
This paper is concerned with a theoretical analysis of the behavior of optically excited spin currents in bilayer and multilayer systems of ferromagnetic and normal metals. As the propagation, control and manipulation of the spin currents …
View article: Laser-induced Creation of antiferromagnetic 180-degree domains in NiO/Pt bilayers
Laser-induced Creation of antiferromagnetic 180-degree domains in NiO/Pt bilayers Open
We demonstrate how the antiferromagnetic order in heterostructures of NiO/Pt thin films can be modified by optical pulses. We irradiate our samples with laser light and identify an optically induced creation of antiferromagnetic domains by…
View article: Fundamentals of Scanning Surface Structuring by Ultrashort Laser Pulses: From Electron Diffusion to Final Morphology
Fundamentals of Scanning Surface Structuring by Ultrashort Laser Pulses: From Electron Diffusion to Final Morphology Open
Industrial use of ultrashort pulse surface structuring would significantly increase by effective utilization of the average laser powers available currently. However, the unexplained degradation of surfaces processed with numerous pulses a…
View article: Influence of Electronic Non-Equilibrium on Energy Distribution and Dissipation in Aluminum Studied with an Extended Two-Temperature Model
Influence of Electronic Non-Equilibrium on Energy Distribution and Dissipation in Aluminum Studied with an Extended Two-Temperature Model Open
When an ultrashort laser pulse excites a metal surface, only a few of all the free electrons absorb a photon. The resulting non-equilibrium electron energy distribution thermalizes quickly to a hot Fermi distribution. The further energy di…
View article: Indirect optical manipulation of the antiferromagnetic order of insulating NiO by ultrafast interfacial energy transfer
Indirect optical manipulation of the antiferromagnetic order of insulating NiO by ultrafast interfacial energy transfer Open
We report the ultrafast, (sub)picosecond reduction of the antiferromagnetic order of the insulating NiO thin film in a Pt/NiO bilayer. This reduction of the antiferromagnetic order is not present in pure NiO thin films after a strong optic…
View article: Influence of diffusive transport on ultrafast magnetization dynamics
Influence of diffusive transport on ultrafast magnetization dynamics Open
We study the influence of transport effects on time- and space-resolved magnetization dynamics in a laser-excited thick nickel film. We explicitly include diffusive heat transport and spin-resolved charge transport as well as Seebeck and P…