Photoexcitation of electronic instabilities in one-dimensional charge-transfer systems

TL;DR

This study uses advanced simulations to show that photoexcitation in one-dimensional charge-transfer systems predominantly enhances the 4k_F electronic instability, indicating potential for optoelectronic switching applications.

Contribution

It demonstrates that photoexcitation selectively amplifies the 4k_F instability in a charge-transfer system, revealing a dominant electronic response regardless of excitation details.

Findings

Large enhancement of 4k_F instability upon photoexcitation

2k_F state remains largely unaffected

Potential for optoelectronic switching devices

Abstract

We investigate the real-time dynamics of photoexcited electronic instabilities in a charge-transfer system model, using the time-dependent density matrix renormalization group method. The model of choice was the quarter-filled one-dimensional extended Peierls-Hubbard Hamiltonian interacting with classical few-cycle electromagnetic radiation. The results show that only one electronic instability drives the main features of the photogenerated time-dependent behavior. Indeed, the photoresponse of the system shows a large enhancement of the $4k_F$ (bond and charge) instability whereas the $2k_F$ state remains largely unaffected. This conclusion holds regardless of the nature of the optical excitations and whether the system is perturbed resonantly or not. Our results suggest potential applications of charge-transfer systems with slow phononic dynamics as optoelectronic switching devices.