Ultrafast destruction and recovery of the spin density wave order in iron based pnictides: a multi-pulse optical study

TL;DR

This study uses ultrafast optical techniques to investigate how spin density wave order in iron-based pnictides is rapidly destroyed and recovered, revealing the role of optical phonons in the process.

Contribution

It introduces a multi-pulse femtosecond optical approach combined with an extended three-temperature model to analyze spin density wave dynamics in iron-based superconductors.

Findings

Optical phonons significantly influence the recovery of spin density wave order.

The destruction and recovery dynamics depend on excitation density.

The extended three-temperature model effectively describes the observed phenomena.

Abstract

We report on systematic excitation-density dependent all-optical femtosecond time resolved study of the spin-density wave state in iron-based superconductors. The destruction and recovery dynamics are measured by means of the standard and a multi-pulse pump-probe technique. The experimental data are analyzed and interpreted in the framework of an extended three temperature model. The analysis suggests that the optical-phonons energy-relaxation plays an important role in the recovery of almost exclusively electronically driven spin density wave order.