Photo-induced insulator-metal transition in paramagnetic (V${}_{1-x}$Cr${}_x$)${}_2$O${}_3$

Abstract

Pump-probe experiments with femtosecond time resolution allow to disentangle the electronic dynamics from the lattice response and thus provide valuable insights into the non-equilibrium behavior of correlated materials. In Cr-doped V${}_2$O${}_3$, a multi-orbital Mott-Hubbard material which has been intensively investigated for decades, time-resolved experiments reported a photo-induced insulator-metal transition leading to a transient metal state with nonthermal properties. Here, we combine non-equilibrium dynamical mean-field theory with realistic first principles modeling to simulate the ultrafast response of this material to a laser excitation. Our calculations reproduce the insulating initial state, with orbital occupations in agreement with experiment, and reveal an ultrafast pump-induced gap filling associated with a charge reshuffling between the $e_g^{\pi }$ and $a_{1g}$ orbitals. However, in contrast to the related compound VO${}_2$, the electronic system thermalizes within a few tens of femtoseconds and we find no evidence for the existence of a metastable nonthermal metal. This suggests that the reported nonthermal behavior in the experiments may be associated with the mismatch between the electronic and lattice temperatures.

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Cited by in corpus (4)

• Photo-induced nonequilibrium states in Mott insulators
• Exploring the Electronic Nature of Spinel Oxides: A Review of Their Electron Interactions and Prospects
• Self-Consistent Coulomb Interactions from Constrained Dynamical Mean-Field Theory
• Ultrafast Electronic Structure Engineering in 1$T$-TaS${}_2$: Role of Doping and Amplitude Mode Dynamics