Controlling the collective properties of solids with light
In this talk, I will discuss how coherent electromagnetic radiation at infrared and TeraHertz frequencies can be used to coherently rearrange atoms within the crystal lattice of a solid. The motion of atoms is large, and the lattice dynamics is discussed in terms of nonlinear phononics. We control metal insulator transitions, magnetic phenomena, superconductivity and ferroelectricity dynamically. I will also discuss how femtosecond x-ray beams from free electron lasers are integral to these studies, and are used to image structures during these non-equilibrium processes.