Using Nonequilibrium Dynamics to Probe Competing Orders in a Mott-Peierls System

TL;DR

This paper investigates the nonequilibrium dynamics of a photoexcited Mott-Peierls system to understand how competing orders influence phase transitions and excitations, revealing momentum-dependent coupling effects.

Contribution

It introduces a method to analyze the coupling between electrons and bosonic modes in a nonequilibrium setting of a Mott-Peierls system, highlighting momentum-dependent effects.

Findings

Anti-phase dynamics near transition point

Coupling strength affects static structure factors

Uneven bosonic mode softening near $k_F$

Abstract

Competition between ordered phases, and their associated phase transitions, are significant in the study of strongly correlated systems. Here we examine one aspect, the nonequilibrium dynamics of a photoexcited Mott-Peierls system, using an effective Peierls-Hubbard model and exact diagonalization. Near a transition where spin and charge become strongly intertwined, we observe anti-phase dynamics and a coupling-strength-dependent suppression or enhancement in the static structure factors. The renormalized bosonic excitations coupled to a particular photoexcited electron can be extracted, which provides an approach for characterizing the underlying bosonic modes. The results from this analysis for different electronic momenta show an uneven softening due to a stronger coupling near $k_F$. This behavior reflects the strong link between the fermionic momenta, the coupling vertices, and ultimately the bosonic susceptibilities when multiple phases compete for the ground state of the system.