Advances in light sources and time resolved spectroscopy have made it possible to strongly excite electronic and ionic degrees of freedom and to observe resulting changes in electronic properties. After an introduction to the general issues and a classification of the different types of experiment the talk will present theoretical results relating to the generation of a long-lived metallic phase by carrier photoexcitation and the generation of a transient superconducting phase by phonon excitation. For the electronic excitation case we demonstrate a route to a self-consistently stabilized nonequilibrium phase. For the phonon excitation case we present a new possibility for transducing a pumped zero momentum phonon into a a change in electronic properties which is independent of the sign of the bare electron-phonon coupling and has a magnitude proportional to the degree of laser-induced phonon excitation. Reasonable excitation amplitudes lead to non-negligible attractive interactions that may cause significant transient changes in electronic properties including superconductivity. The mechanism is generically applicable to a wide range of systems, offering a promising route to manipulating and controlling electronic phase behavior in novel materials. This work has been performed in collaboration with Z. He, E. Wilner, D. Kennes and D. Reichman and is supported by the US National Science Foundation under grant DMR-1308236 and the Department of Energy under grants DE-SC00123175 and SC-0012592.


Seminar, December 5, 2016, 15:00. ICFO’s Seminar Room

Hosted by Prof. Simon Wall