Speaker

Lieu

LPS, amphi moyen
Orsay

Date

10 Oct 2022
Expired!

Heure

11h00 - 12h00

Siham Benhabib I Ultrafast generation of hidden phases via energy-tuned electronic photoexcitation in magnetite

EPFL, Suisse

Metal-Insulator transitions in non-adiabatic conditions can evolve through higher energy intermediate states that are difficult to observe and control. By monitoring the ultrafast out-of-equilibrium evolution of the crystal structure of magnetite with electron diffraction, I show that MIT can evolve through different paths by selecting the electronic excitation with light. Near-infrared (800 nm) light creating d-d electronic transitions is found to induce the destruction of the long-range zigzag network of the trimerons and generate a phase separation between cubic-metallic and monoclinic-insulating regions. Instead, visible light (400 nm) further promotes the long-range order of the trimerons by stabilizing the charge density wave fluctuations through the excitation of the oxygen 2p to copper 3d charge transfer and, thus, fosters a reinforcement of the monoclinic insulating phase. Our experiments demonstrate that tailored light pulses can drive strongly correlated materials into different hidden phases, influencing the lifetime and emergent properties of the intermediate states.

In this presentation, I will discuss the possible scenarios responsible for such differences in the dynamic responses