Speaker
Description
Attosecond Physics explores ways to follow and control matter with unprecedented temporal resolution (1 attosecond= 10-18 s.). Strong laser fields used to apply forces on the sub-cycle timescale, together with the availability of tabletop attosecond soft x-ray pulses, now open avenues for time-resolving ultrafast dynamics on the unexplored attosecond timescale [1, 2]. In this first attosecond pump - attosecond probe experiment, an isolated 100 eV attosecond pulse initiates an Auger decay followed by an attosecond broadband (250-1100nm) optical pulse. The observable is the soft x-ray absorption spectrum as a function of pump-probe delay. A first experiment in krypton atoms allows us to model the effect of the optical probe as a gate of the Auger electronic dipole, a universal analog to the frequency-resolved optical gating technique [3]. Applying our attosecond x-ray absorption near-edge spectroscopy (AXANES) to the L-edge of fused silica enables us to directly observe and control sub-femtosecond core-excitons in solids, laying the foundation of soft x-ray excitonics.
[1] J. B. Bertrand et al., Nature Physics 9, 174 (2013).
[2] S. R. Leone et al., Nature Photonics 8, 162 (2014).
[3] R. Trebino, FROG, Kluwer Academic Publishers, Boston (2002).
[4] A. Moulet, J. B. Bertrand, T. Klostermann, A. Guggenmos, N. Karpowicz, E. Goulielmakis, Science 357, 1134-1138 (2017).
