158 citations · 653 across the 35 of their papers we have counts for
35 papers
Direct High-Magnetic-Field Coupling to Stripe Order in a Cuprate Superconductor
Leonardo Martinelli, Izabela Biało, Jens Oppliger +47
Superconductivity in cuprates emerges out of a complex normal state that hosts density waves, pseudogap physics, and strange metal properties. Here, we access this normal state by…
Nanoscale Confinement Enhances Ultrafast Demagnetization
Yoav William Windsor, Tobias Lojewski, Moumita Kundu +21
Nanoscale miniaturization has revolutionized the field of spintronics by enabling exponential growth in areal bit density. A similar leap is also expected in device speeds through…
Defect Detection in Magnetic Systems Using U-Net and Statistical Measures
Ross Knapman, Atreya Majumdar, Nasim Bazazzadeh +4
Local material inhomogeneities can strongly influence magnetization dynamics and macroscopic magnetic properties, yet detecting such defects from magnetic imaging data remains chal…
Analysis of long-lived effects in high-repetition-rate stroboscopic transient X-ray absorption experiments on thin films
Tobias Lojewski, Loïc Le Guyader, Naman Agarwal +41
Time-resolved X-ray absorption spectroscopy (tr-XAS) has been shown to be a versatile measurement technique for investigating non-equilibrium dynamics. Novel X-ray free electron la…
Femtosecond spin-state switching dynamics of spin-crossover molecules condensed in thin films
Lea Kämmerer, Gérald Kämmerer, Manuel Gruber +22
The photoinduced switching of Fe(II)-based spin-crossover complexes from singlet to quintet takes place at ultrafast time scales. This a priori spin-forbidden transition triggered…
Voltage-driven 90 switching of bulk perpendicular magnetic anisotropy in ferrimagnets
Zhengyu Xiao, Ruiwen Xie, Fernando Maccari +18
Unravelling the mechanism behind bulk perpendicular magnetic anisotropy (PMA) in amorphous rare earth-transition metal films has proven challenging. This is largely due to the inhe…
Photo-induced charge-transfer renormalization in NiO
Tobias Lojewski, Denis Golez, Katharina Ollefs +21
Photo-doped states in strongly correlated charge transfer insulators are characterized by - and - interactions and the resulting intertwined dynamics of charge excitati…
Element-Specific Study of Magnetic Anisotropy and Hardening in SmCoCu Thin Films
Georgia Gkouzia, Damian Günzing, Ruiwen Xie +10
This work investigates the effect of copper substitution on the magnetic properties of SmCo thin films synthesized by molecular beam epitaxy. A series of thin films with vary…
Local magnetic and geometric structure in Mn-doped La(Fe,Si)13
Benedikt Eggert, Johanna Lill, Damian Günzing +11
Magnetic cooling has the potential to replace conventional gas compression refrigeration. Materials such as La(Fe,Si) exhibit a sizeable first-order magnetocaloric effect, a…
Formation of Core-Shell Precipitates in off-stochiometric Ni-Mn-Sn Heusler alloys probed through the induced Sn-moment
Benedikt Eggert, Aslı Çakır, Damian Günzing +7
The Shell-ferromagnetic effect originates from the segregation process in off-stochiometric Ni-Mn-based Heusler. In this work, we investigate the precipitation process of L2-or…
Identifying grain boundary and intragranular pinning centres in Sm2(Co,Fe,Cu,Zr)17 permanent magnets to guide performance optimisation
Stefan Giron, Nikita Polin, Esmaeil Adabifiroozjaei +21
Permanent magnets draw their properties from a complex interplay of chemical composition and phase, each with their associated intrinsic magnetic properties. Gaining an understandi…
A multi-stage, first-order phase transition in LaFe11.8Si1.2: interplay between the structural, magnetic and electronic degrees of freedom
K. P. Skokov, A. Y. Karpenkov, D. Y. Karpenkov +11
Alloys with a first-order magnetic transition are central to solid-state refrigeration technology, sensors and actuators, or spintronic devices. The discontinuous nature of the tra…
A Rate Model of Electron Populations for Non-linear High-Fluence X-ray Absorption Near-Edge Spectra
Robin Y. Engel, Markus Scholz, Jan O. Schunck +1
Absorbing a focused, femtosecond X-ray pulse from a Free-Electron Laser (FEL) can lead to extreme electronic excitations in solids. This excitation drives changes of the electronic…
Electron Dynamics at High-Energy Densities in Nickel from Non-linear Resonant X-ray Absorption Spectra
Robin Y. Engel, Oliver Alexander, Kaan Atak +40
The pulse intensity from X-ray free-electron lasers (FELs) can create extreme excitation densities in solids, entering the regime of non-linear X-ray-matter interactions. We show L…
Photon shot-noise limited transient absorption soft X-ray spectroscopy at the European XFEL
Loïc Le Guyader, Andrea Eschenlohr, Martin Beye +61
Femtosecond transient soft X-ray Absorption Spectroscopy (XAS) is a very promising technique that can be employed at X-ray Free Electron Lasers (FELs) to investigate out-of-equilib…
The interplay of local electron correlations and ultrafast spin dynamics in fcc Ni
Tobias Lojewski, Mohamed F. Elhanoty, Loïc Le Guyader +48
The complex electronic structure of metallic ferromagnets is determined by a balance between exchange interaction, electron hopping leading to band formation, and local Coulomb rep…
Autonomous atomic Hamiltonian construction and active sampling of x-ray absorption spectroscopy by adversarial Bayesian optimization
Yixuan Zhang, Ruiwen Xie, Teng Long +4
X-ray absorption spectroscopy (XAS) is a well-established method for in-depth characterization of the electronic structure due to its sensitivity to the local coordination and elec…
Complete crystallographic, spin-electronic and magnetic structure of (Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)3O4: Unraveling the suppression of entropy in high entropy oxides
Abhishek Sarkar, Benedikt Eggert, Ralf Witte +12
High entropy oxides (HEOs) are a rapidly emerging class of functional materials consisting of multiple principal cations. The original paradigm of HEOs assumes cationic occupations…
A full gap above the Fermi level: the charge density wave of monolayer VS2
Camiel van Efferen, Jan Berges, Joshua Hall +15
In the standard model of charge density wave (CDW) transitions, the displacement along a single phonon mode lowers the total electronic energy by creating a gap at the Fermi level,…
Static magnetic proximity effects and spin Hall magnetoresistance in Pt/YFeO and inverted YFeO/Pt bilayers
Stephan Geprägs, Christoph Klewe, Sibylle Meyer +13
The magnetic state of heavy metal Pt thin films in proximity to the ferrimagnetic insulator YFeO has been investigated systematically by means of x-ray magnetic…
Role of intermediate 4 states in tuning the band structure of high entropy oxides
Abhishek Sarkar, Benedikt Eggert, Leonardo Velasco +8
High entropy oxides (HEOs) are single phase solid solutions consisting of 5 or more cations in approximately equiatomic proportions. In this study, we show reversible control of op…
Magnetic properties of rare earth and transition metal based perovskite type high entropy oxides
Ralf Witte, Abhishek Sarkar, Leonardo Velasco +7
High entropy oxides (HEO) are a recently introduced class of oxide materials, which are characterized by a large number of elements (i.e. five or more) sharing one lattice site whi…
Magnetic response of FeRh to static and dynamic disorder
Benedikt Eggert, Alexander Schmeink, Johanna Lill +10
Changes of the magnetic and crystal structure on the microscopic scale in 40 nm FeRh thin films have been applied to investigate the phenomena of a disorder induced ferromagnetism…
Influence of hydrogenation on the vibrational density of states of magnetocaloric
Alexandra Terwey, Markus E. Gruner, Werner Keune +14
We report on the impact of magnetoelastic coupling on the magnetocaloric properties of LaFeSiH in terms of the vibrational density of states, which we dete…