"Coherent optical control and nonlinear probing of strongly correlated materials"

Speaker: Roman Mankowsky, Paul Scherrer Institute

When: October 13, 2017 (Fri), 12:00PM to 01:30PM (add to my calendar)
Location: SCI 352
Hosted by: Wanzheng Hu

This event is part of the Condensed Matter Theory Seminar Series.

Mid-infrared optical pulses can resonantly drive selected vibrational modes in solids to deform their crystal structure. In strongly correlated materials, this method has been used to melt electronic and magnetic order, drive insulator-to-metal transitions, and transiently induce superconductivity. Free Electron Lasers have been key in identifying the lattice dynamics underlying these transitions.

In this talk, I will first review nonlinear phononics and discuss its role in the phenomenon of light-induced superconductivity. I will then present recent studies, in which resonant lattice excitation was used to control the polarization of ferroelectric materials on femtosecond timescales. These studies are a first step toward ultrafast reversible switching. In the last part of the lecture, I will focus on the excitation of highly nonlinear lattice dynamics, a new technique which allowed us to reconstruct the interatomic lattice potential of a solid and benchmark first principle calculations.