Ultrafast metal-to-insulator switching in a strongly correlated system

TL;DR

This paper demonstrates that ultrafast light-induced switching from a metal to a Mott insulator is achievable in a correlated system, with minimal heating, using dynamical mean-field theory on a model of LaTiO$_{3+x}$.

Contribution

It introduces a method to induce rapid metal-to-insulator transitions via optimized photo-doping, maintaining low effective temperature in the final state.

Findings

Ultrafast metal-to-insulator transition achieved through photo-doping.

Final insulator state has nearly the same temperature as the initial metal.

The process minimizes heating during the transition.

Abstract

Light-manipulation of correlated electronic phases in solids offers the tantalizing prospect of realizing electronic devices operating at the ultrafast time-scale. In this context, the experimental realization of non-equilibrium transitions from a metal to a band or Mott insulator has shown to be particularly elusive. Using dynamical mean-field theory, we study a simple model representing the main physical properties of the oxygen-enriched compound LaTiO$_{3+x}$. By properly optimizing the photo-doping of electrons from a low-energy band into the valence states of the system, we show it is possible to induce a valence transition from a correlated metallic state to a Mott insulator at ultrashort time scales and to contain the heating during this process, with the final non-thermal valence insulator having almost the same effective temperature of the starting metal.