Hannover 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
A: Fachverband Atomphysik
A 5: Attosecond physics
A 5.3: Vortrag
Montag, 18. März 2013, 14:45–15:00, B 305
On imaging the instantaneous electron density with ultrafast x-rays: Is it possible? — •Jan Malte Slowik1,2, Gopal Dixit1, and Robin Santra1,2 — 1Center for Free-Electron Laser Science, DESY, Hamburg, Germany — 2Department of Physics, University of Hamburg, Hamburg, Germany
Tracing the dynamical evolution of the electron density has enormous relevance to understanding ultrafast phenomena occurring for example in chemical and biological processes. Scattering of ultrashort x-ray pulses from an electronic wavepacket would appear to be an obvious approach to image the electronic motion in real-time and real-space. However, the scattering pattern in the far-field regime does not encode the instantaneous electron density of the wavepacket, but probes spatio-temporal density-density correlations. Here, we propose a possible way to image the instantaneous electron density of the wavepacket via ultrafast x-ray phase contrast imaging. Moreover, we show that inelastic scattering processes, which plague ultrafast scattering in the far-field regime, do not contribute in ultrafast x-ray phase contrast imaging as a consequence of an interference effect. Our general findings will be illustrated by means of a wavepacket that lies in the time and energy range of the dynamics of valence electrons in complex molecular and biological systems. This approach offers a potential to image not only instantaneous snapshots of electron dynamics in non-stationary quantum systems, but also the Laplacian of these snapshots which provides information about the complex bonding and topology of the charge distributions in the systems.