Dresden 2020 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 61: Ultrafast Dynamics of Light-Driven Systems (joint session TT/MA)

TT 61.10: Talk

Thursday, March 19, 2020, 17:30–17:45, HSZ 201

Ultrafast metal-to-insulator switching in a strongly correlated system — •Francesco Grandi and Martin Eckstein — Department of Physics, University of Erlangen-Nürnberg, 91058 Erlangen, Germany

Several experiments have shown the possibility to induce an ultrafast insulator-to-metal phase transition in correlated materials. Instead, it remains debated how to experimentally realize an ultrafast phase transition in the opposite direction, i.e. a metal-to-insulator phase change. Developing a protocol that can lead to such a transition is relevant for the realization of a Mottronic device able to operate at the ultrafast time scales. A possible candidate for the realization of this scenario is the oxygen-enriched LaTiO_3+x, a correlated metal close to the Mott insulator LaTiO₃.
Here, we consider an effective model that we believe captures the main physical properties of LaTiO_3+x. We describe the photo-doping of electrons into the valence bands of the material from the low-lying oxygens 2p-derived band using non-equilibrium Dynamical Mean-Field Theory. By applying a suitably designed chirped-pulse that leads to dipolar excitations, we analyze how fast we can induce the metal-to-insulator transition and how far the final state is from a thermal configuration.