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.