相关论文: Electronic origin of x-ray absorption peak shifts
We use a pump-probe scheme to measure the time evolution of the C K-edge X-ray absorption spectrum (XAS) from CO/Ru(0001) after excitation by an ultrashort high-intensity optical laser pulse. Due to the short duration of the X-ray probe…
We report a novel mechanism, consisting of redistribution of valence electrons near the Fermi level, during interactions of intense femtosecond X-ray pulses with a Co/Pd multilayer. The changes in Co 3d valence shell occupation were…
Experimental investigations of ultrafast magnetization dynamics increasingly employ resonant magnetic spectroscopy in the ultraviolet spectral range. Besides allowing to disentangle the element-specific transient response of functional…
The electronic excitation occurring on adsorbates at ultrafast time scales from optical lasers that initiate surface chemical reactions is still an open question. Here, we report the ultrafast temporal evolution of X-ray absorption…
In pump-probe experiments an intensive laser pulse creates non-equilibrium excited electron distributions in the first few hundred femtoseconds after the pulse. The influence of non-equilibrium electron distributions caused by a pump laser…
Ultrashort optical pulses can trigger a variety of non-equilibrium processes in magnetic thin films affecting electrons and spins on femtosecond timescales. In order to probe the charge and magnetic degrees of freedom simultaneously, we…
In plasma X ray photoelectron spectroscopy emerges as a powerful platform for real time, in situ chemical analysis under conditions relevant to semiconductor processing and other plasma enabled technologies. This study investigates the…
Transient structural changes of Al$_2$O$_3$ on subatomic length scales following irradiation with an intense x-ray laser pulse (photon energy: 8.70 keV; pulse duration: 6 fs; fluence: 8$\times$10$^2$ J/cm$^{2}$) have been investigated by…
Core level binding energies and absorption edges are at the heart of many experimental techniques concerned with element-specific structure, electronic structure, chemical reactivity, elementary excitations and magnetism. X-ray…
Time-resolved absorption spectroscopy as well as magnetic circular dichroism with circularly polarized soft X-rays (XAS and XMCD) are powerful tools to probe electronic and magnetic dynamics in magnetic materials element- and…
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 system over the course of the pulse duration and the…
We study the optical-pump induced ultrafast transient change of the X-ray absorption at the $L_3$ absorption resonances of the transition metals Ni and Fe in Fe$_{0.5}$Ni$_{0.5}$ alloy. We find the effect for both elements to occur…
Recent seminal experiments have utilized time-resolved X-ray absorption spectroscopy (XAS) to investigate the ultrafast photo-induced renormalization of the electron interaction (''Hubbard $U$'') in Mott and charge transfer insulators. In…
Electrolyte-based transistors utilizing ionic liquids/gels have been highly successful in the study of charge-density-controlled phenomena, particularly in oxides. Experimental probes beyond transport have played a significant role, despite…
Rich valleytronics and diverse defect-induced or interlayer pre-bandgap excitonics have been extensively studied in transition metal dichalcogenides (TMDCs), a system with fascinating optical physics. However, more intense high-energy…
The present paper demonstrates the feasibility of X-ray Absorption Spectroscopy (XAS) and X-ray Magnetic Circular Dichroism (XMCD) at high pressure at the Fe-K edge on the ID24 energy dispersive beamline of the ESRF. In 3d transition…
X-ray absorption spectroscopy (XAS) is an explicit probe of the unoccupied electronic structure of materials and an invaluable tool for fingerprinting various electronic properties and phenomena. Computational methods capable of simulating…
The use of advanced X-ray sources plays a key role in the study of dynamic processes in magnetically ordered materials. The progress in X-ray free electron lasers enables the direct and simultaneous observation of the femtosecond evolution…
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 laser (XFEL) facilities like the European XFEL offer increased…
X-ray free-electron lasers (XFELs) have been widely used for applications such as X-ray crystallography and magnetic spin probes because of their unprecedented performance. Recently, time-resolved X-ray magnetic circular dichroism (XMCD)…