Ultrafast Non-thermal Suppression of Ferroelectricity Revealed by Multimodal Spectroscopic Investigation

The interplay between ferroelectric polarization and charge carriers is central to the emergent properties in ferroelectric materials. Despite extensive studies of the impact of carriers on ferroelectricity at equilibrium, the influence of non-equilibrium carrier populations on an ultrafast timescale remains elusive. In this work, we investigated the suppression of ferroelectricity induced by photoexcited carriers in a wide-bandgap ferroelectric. After generating free carriers with intense, tailored laser pulses, we tracked the induced changes in ferroelectric order and lattice dynamics using time-resolved second harmonic generation and femtosecond stimulated Raman spectroscopy, respectively. Rapid yet prolonged reductions of macroscopic polarization and Raman susceptibility were observed and confirmed to originate from non-thermal carrier screening by dilute photoexcited carriers. These results reveal a symmetry-preserving, non-thermal mechanism for ultrafast suppression of ferroelectricity, suggesting routes to control ferroic orders and competing quantum phases.