Photo-Induced Dynamics in Charge-Frustrated Systems

TL;DR

This study investigates how photo-excitation affects charge-ordered states in a frustrated system, revealing distinct dynamics depending on the initial charge order and highlighting the role of charge frustration.

Contribution

It provides the first real-time analysis of photo-induced charge dynamics in frustrated systems using exact diagonalization, distinguishing behaviors of different charge-ordered states.

Findings

Horizontal stripe CO transitions to three-fold CO after photo-excitation.

Vertical stripe CO is weakened but remains stable under irradiation.

Charge frustration influences the distinct photo-induced behaviors.

Abstract

Photo-excited charge dynamics of interacting charge-frustrated systems are studied using a spinless fermion model on an anisotropic triangular lattice. Real-time evolution of the system after irradiating a pump-photon pulse is analyzed by the exact diagonalization method. We focus on photo-excited states in the two canonical charge-ordered (CO) ground states, i.e., horizontal stripe-type and vertical stripe-type COs, which compete with each other owing to the charge frustration. We find that the photo-induced excited states from the two types of COs are distinct. From the horizontal stripe-type CO, a transition to another CO state called the three-fold CO phase occurs. In sharp contrast, the vertical stripe-type CO phase is only weakened by photo-irradiation. Our observations are attributable to the charge frustration effects occurring in the photo-excited states.