Open Positions
Ultrafast Dynamics Lab (PhD students, Master students and diploma students)
Research profile:
Our research is focused on studying the structure and dynamics of biochemical systems in solutions. Currently we are using the Bessy II synchrotron as an x-ray light source giving us access to X-ray pulses in an energy range from 100 to 1500 eV. This energy range covers the K-edge of life elements (oxygen, nitrogen, carbon …) as well as the L-edge of transition metals (first row 3d- elements). We have developed spectrometers allowing us to investigate these elements under physiological conditions (room or body temperature and pressure). Note that soft x-rays require ultra high vacuum and it is not trivial to introduce systems under ambient conditions to be investigated there.
Our previous success allowed us to win an ERC-starter grant for investigating ultra-fast dynamics in solution and at interfaces for chemical and biological applications. This will allow us to proceed on the following two pillar approach for pump and probe measurements:
- Using a laser pump- and a X-ray probe-pulse from the synchrotron, measuring either x-ray transmission or fluorescence. Synchrotron radiation will enable a high intensity probe, but limits the time resolution to 50 ps.
- Using a laser pump- and high-harmonic X-ray probe-pulse, using primarily photoelectron spectroscopy with the possibility to extend the technique to X-ray transmission and fluorescence measurements. The X-ray pulse based on high harmonic generation will be limited in intensity but allows a femto-second time resolution.
Desired qualification:
- Experience with high-harmonic generation
- Experience with X-ray spectroscopy, synchrotron radiation, and vacuum systems
For our new research efforts into time resolved spectroscopy as well as synchrotron based x-ray spectroscopy usually several opportunities for a Master or Bachelor thesis exist.
Also PhD positions become periodically available for current possibilities contact:
emad.aziz@helmholtz-berlin.de
A new PhD position is available as of May 2013 at the Ultrafast Dynamics Lab:
Ultra-Fast Dynamics in Solutions and at Interfaces
The research addresses a wide range of processes occurring under interaction of laser radiation with biochemical molecular systems in solutions. Among these are charge transfer, modification of the geometric and bond structure, electron emission in a strong laser field, and coherent excitation of electronic wave packets in complex systems. A pump-probe laser scheme will be used to investigate dynamics of these processes. Experiments will be conducted with the use of laser sources (Ti: sapphire laser, optical parametric amplifier, high-order harmonic generation setup) available at the newly built laser lab at the Freie Universität Berlin.
