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 V2O3, 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 egπ and a1g orbitals. However, in contrast to the related compound VO2, 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.
@article{arxiv.2404.18819,
title = {Photo-induced insulator-metal transition in paramagnetic (V$_{1-x}$Cr$_{x}$)$_2$O$_3$},
author = {Jiyu Chen and Francesco Petocchi and Viktor Christiansson and Philipp Werner},
journal= {arXiv preprint arXiv:2404.18819},
year = {2024}
}