Colloquium on March 2, 2009

Andrea Cavalleri
Max Planck Research Group for Structural Dynamics
University of Hamburg, DESY

Photo-control in complex solids

In this talk I will cover some of our recent progress in the area of photo-control of strongly correlated electron systems and of new ways to interrogate their dynamics on the ultrafast timescale. I will discuss the use of sub-10 fs pulses to control filling on timescales faster than the latice response, indeed sometimes faster than the inverse of the bandwidth in narrow band Mott Insulators. I will also discuss the use of resonant vibrational excitation to drive ultrafast transitions in the electronic properties without changing the filling. These processes are the ultrafast equivalents of bandwidth controlled and filling controlled transitions, and can teach us about microscopic interactions in new ways. Progress in the use of femtosecond x-ray probes, which are conceptually a straightforward extension of static x-ray and ultrafast optical techniques, but are also technologically very challenging, will also be reviewed.