Ultrafast charge dynamics in bulk alpha-Fe₂O₃

Details of the ultrafast charge dynamics in oxides is crucial for interpretation of recent experimental data and for potential application of such materials in modern technologies. In this talk, we present results for ultrafast charge dynamics in laser pulse-excited antiferromagnet alpha-Fe₂O₃ obtained with the combined time-dependent density-functional theory and dynamical mean-field theory approach. In particular, we have calculated the time-resolved occupancies of the involved O(p) valence and Fe(d) conduction orbitals and demonstrated that due to strong electron-electron correlations there is delay of a few femtosecond in the charge accumulation in the electron and hole Fe(d) orbitals as compared to the O(p) hole orbitals. The obtained results for the ultrafast dynamics helps explain the attosecond transient absorption spectroscopy data for alpha-Fe₂O₃ which demonstrate ultrafast modification of the absorption spectra due to ligand-to-metal charge transfer. Our approach can be further extended to treat the femtosecond- and sub-femtosecond resolved dynamics of photoexcitation in strongly correlated materials, specifically, photo-induced insulator-to-metal transitions