"Nonlinear phononics: Coherent control of functional solids"

Note: *Coffee will be served at 3pm; Talk begins at 3:30pm
Speaker: Andrea Cavalleri, University of Hamburg, University of Oxford

When: December 12, 2017 (Tue), 03:30PM to 04:45PM (add to my calendar)
Location: SCI 109
Hosted by: Wanzheng Hu

This event is part of the Physics Department Colloquia Series.

In this lecture, I will discuss how coherent electromagnetic radiation at infrared and TeraHertz frequencies can be used to drive atoms within the crystal lattice of a solid. For strong enough fields, the response of the lattice is nonlinear, and energy flows between different normal modes of the solid.

I will discuss how phononics can be used to manipulate ferroelectricity, magnetism and superconductivity, and will reflect on the underlying mechanisms, which are understood for some but not all these phenomena. Throughout the lecture, I will also discuss how femtosecond x-ray beams from free electron lasers allow for the reconstruction of atomic structure during these non-equilibrium processes.

Först, M. et al. Nonlinear phononics as a new ultrafast route to lattice control. Nat. Phys. 7, 854-856 (2011). Subedi, A. Cavalleri, A., Georges, A. Theory of nonlinear phononics for the coherent light control of solids Phys. Rev. B (2014). Mankowsky, R., von Hoegen, A., Först, M. & Cavalleri, A. Ultrafast reversal of the ferroelectric polarization. Phys. Rev. Lett. , (2017). Nova, T. F. et al. An effective magnetic field from optically driven phonons. Nature Physics, 13, 132–136 (2017) Fausti, D. et al. Light induced Superconductivity in a Stripe-ordered Cuprate. Science 331, 189-191 (2011). Mitrano, M. et al. Possible light-induced superconductivity in K3C60 at high temperature. Nature 530, 461-464 (2016). Mankowsky, R. et al. Nonlinear lattice dynamics as a basis for enhanced superconductivity in YBa2Cu3O6.5. Nature 516, 71-73 (2014).