Investigating the role of anion polarizability in Fe-based superconductors via light-matter interaction

TL;DR

This study explores how external optical excitation can modulate electron interactions in Fe-based superconductors by affecting anion polarizability, providing insights into the role of polarizable ions in superconductivity.

Contribution

It demonstrates that light-matter interaction can significantly influence carrier interactions via anion polarizability in a simplified FeAs layer model.

Findings

External optical fields can modulate electron interactions.

Perturbative fields much smaller than internal fields are effective.

Potential to explore anion polarizability's role in superconductivity.

Abstract

The polarizability of nearby ions may have a significant impact on electron interactions in solids, but only limited experimental data are available to support this picture. In this work, using a highly simplified description of the prototypical FeAs superconducting layer, we show how external optical excitation of the As 4p-5s splitting can lead to a significant modulation of the polarization-mediated effective interactions between carriers. Our results suggest that even perturbative external fields, approximately two orders of magnitude smaller than the internal field generated by charge carriers, might enable the exploration of the role of the anion's polarizability in determining the correlated physics, although more detailed modeling is needed to decide optimal ways to achieve this.