Long-lived photoinduced response observed under extreme photoexcitation densities in a one-dimensional Peierls insulator

Abstract

One-dimensional metal-halide compounds provide model systems to investigate the manner in which coupling between elementary degrees of freedom—here, electronic and vibrational—result in instabilities that give rise to both chemical and structural rearrangements. Here, we employ “single-shot” pump-probe spectroscopy to examine a one-dimensional platinum iodide compound (PtI(en)) under far-from-equilibrium conditions where repeated photoexcitation results in sample damage. It presents evidence for a distinct collective excited state lasting more than 100 ps upon self-trapped exciton generation at high densities, as measured by electronic signal amplitudes and phonon properties.