Nonlinear lattice relaxation of photoexcited diplatinum-halide chain compounds

TL;DR

This paper investigates the relaxation mechanisms of photoexcited states in diplatinum-halide chains using a theoretical model, revealing complex decay pathways involving polarons, excitons, and solitons, with implications for optical properties.

Contribution

It introduces a detailed theoretical analysis of relaxation processes in diplatinum-halide chains, highlighting the simultaneous generation of multiple quasiparticles and predicting optical conductivity during decay.

Findings

High-energy excitations relax into polarons.

Excitons decay into luminescence or divide into solitons.

Simulated optical conductivity supports experimental verification.

Abstract

In order to reveal the relaxation mechanism of photogenerated charge-transfer excitations in quasi-one-dimensional halogen-bridged diplatinum complexes, we calculate the low-lying adiabatic potential energy surfaces of a one-dimensional extended Peierls-Hubbard model. High-energy excitations above the electron-hole continuum may relax into polarons, while excitons pumped within the optical gap are self-localized and then either decay by luminescence or divide into solitons. Neutral solitons, charged solitons, and polarons may be simultaneously photogenerated in a diplatinum-halide chain, which has never been observed in any conventional platinum-halide chain. Optical conductivity is also simulated along the decay paths for experimental verification.