Real-time probing of structural dynamics in solids
Prof. Dr. T. Elsässer (Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin)

Diffraction of x-rays from crystalline materials allows to determine time averaged equilibrium structures with high precision. Function of physical, chemical, and biological systems is frequently connected with nonequilibrium processes, involving ultrafast changes of electronic and/or nuclear structure. X-ray diffraction with a femtosecond time resolution has developed into an important tool to probe such changes most directly and unravel the mechanisms behind them. The interplay of coherent lattice motions and transient electric polarizations in nanolayered ferroelectrics is probed in real-time, revealing the coupling mechanisms and making polarization switching on ultrafast time scales possible. As a second example, transient structural changes connected with the solvation of molecular dipoles in crystals will be addressed.

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N. Zhavoronkov et al., Opt. Lett. 30, 1737 (2005).