# Photoinduced charge-order melting dynamics in a one-dimensional interacting Holstein model

## TL;DR

This study investigates the ultrafast dynamics of charge order melting in a one-dimensional fermion-phonon system after optical excitation, revealing different mechanisms depending on phonon frequency and confirming the soliton-based interpretation.

## Contribution

It provides a detailed numerical analysis of photoinduced charge order melting in a one-dimensional Holstein model, highlighting the roles of quantum phonons and soliton dynamics under different conditions.

## Key findings

- Charge order melting is explained by soliton propagation without phonons.
- Large phonon frequency induces polaronic soliton-driven melting.
- Small phonon frequency involves energy transfer and soliton band motion.

## Abstract

Transient quantum dynamics in an interacting fermion-phonon system are investigated. In particular, a charge order (CO) melting after a short optical-pulse irradiation and roles of the quantum phonons on the transient dynamics are focused on. A spinless-fermion model in a one-dimensional chain coupled with local phonons is analyzed numerically. The infinite time-evolving block decimation algorithm is adopted as a reliable numerical method for one-dimensional quantum many-body systems. Numerical results for the photoinduced CO melting dynamics without phonons are well interpreted by the soliton picture for the CO domains. This interpretation is confirmed by the numerical simulation for an artificial local excitation and the classical soliton model. In the case of the large phonon frequency corresponding to the antiadiabatic condition, the CO melting is induced by propagations of the polaronic solitons with the renormalized soliton velocity. On the other hand, in the case of the small phonon frequency corresponding to the adiabatic condition, the first stage of the CO melting dynamics occurs due to the energy transfer from the fermionic to phononic systems, and the second stage is brought about by the soliton motions around the bottom of the soliton band. Present analyses provide a standard reference for the photoinduced CO melting dynamics in low-dimensional many-body quantum systems.