Coherent scattering of x-rays allows to obtain real space information via (iterative) phasing of the diffraction pattern or via direct phase detection by interference with a reference beam (holography). Regarding „movies“ of dynamic processes, reproducibly triggered dynamics is accessible via pump-probe schemes, as they allow to collect sufficient statistics via repetition of the experiment....
In this talk I will try to give a brief overview of recent progress in time-resolved implementation of X-ray spectroscopic and scattering methods at X-ray free electron lasers and synchrotrons. I will focus the applications on condensed-phase chemical systems and timescales spanning from femtoseconds to nanoseconds.
About the speaker:
Wojciech Gawelda is a distinguished “Beatriz Galindo”...
X-ray methods are powerful to study lattice, electron and spin properties of materials and get information on the dynamics by spectroscopic techniques in the steady state. In recent years, X-ray Free Electron Lasers extended the view on the dynamics to the ultrafast time scale, as these sources provide us with ultrashort fs x-ray pulses that extend spectroscopic techniques into time domain,...
The conversion of light to fundamental excitations of matter is governed by the build-up of electronic coherences and their dephasing to excited quasiparticles due to scattering processes, which occur on atto- and femtosecond timescales. Disentangling the interplay of these mechanisms, and how they lead to a specific flow of energy inside a material, is extremely challenging since many of...
Few cycle optical fields at allow manipulating electronic and spin degrees of freedom in solid state systems at optical clock rates faster than de-coherence. As an example I will discuss ultrafast bidirectional energy transfer between a light-field and the band-structure of silica and optically induced spin transfer in ferromagnetic heterostructures.
About the speaker:
Martin Schultze has...
The quest of achieving complete control over the generation of coherent x-ray sources has driven the efforts over the scientific community during the last years due to their unique ability to capture the fastest electronic and spin dynamics in a wide variety of materials. Among other x-ray sources, high-harmonic generation (HHG) stands as a robust mechanism to generate highly spatially and...
X-ray photon correlation spectroscopy (XPCS) enables the study of sample dynamics between micrometer and atomic length scales. As a coherent scattering technique, it significantly benefits from the increased brilliance of the next-generation synchrotron radiation and Free-Electron Laser (FEL) sources.
In my presentation I will introduce the XPCS concepts and show some recent examples of...
Although often neglected the coupling of spin and lattice motion plays a role on many length and timescales. Novel spintronic applications aim at controlling magnetization precession and spin currents via lattice strain waves while also angular momentum transfer via the Einstein-de Haas effect can play a role. In this presentation I will give an overview how synchrotrons and x-ray free...
Scanning Transmission X-ray Microscopy (STXM) is
an established method for high resolution (down to <20nm) microscopy with chemical and magnetic imaging using NEXAFS / XMCD as contrast mechanism. Due to its scanning probe nature, this method can utilize specialized detectors for advanced imaging possibilites. Examples shown will include the use of fast single photon detectors for time...
Quantum materials host exotic properties that make them highly desirable for applications, but the complex internal interactions that lead to these properties also make them difficult to understand. Ultrafast spectroscopy is a promising route to disentangle the important degrees of freedom in such materials, but spontaneous phase separation and other nanoscale dynamics mean both temporally and...
With the advent of diffraction limited light sources, coherent X-rays will play an important role in understanding and characterizing nanoscale magnetic surfaces and interfaces with unique and novel spin textures. Coherent X-ray scattering give rise to speckle pattern that contain unique finger-print about the sample heterogeneity. In this talk I will show various examples to demonstrate how...
