Probing the pairing symmetry of the iron pnictides with electronic Raman scattering

TL;DR

This paper investigates the superconducting gap symmetry in iron pnictides using electronic Raman scattering, analyzing how different gap structures influence Raman spectra to identify gap characteristics.

Contribution

It provides theoretical calculations of Raman intensities for various polarization states to distinguish gap symmetries in iron-based superconductors.

Findings

Calculated Raman spectra for different gap models

Identified spectral features associated with gap nodes

Provided guidance for experimental gap symmetry determination

Abstract

An important issue in the study of the iron-arsenic based superconductors is the symmetry of the superconducting gap, a problem complicated by multiple gaps on different Fermi surface sheets. Electronic Raman scattering is a flexible bulk probe which allows one in principle to determine gap magnitudes and test for gap nodes in different regions of the Brillouin zone by employing different photon polarization states. Here we calculate the clean Raman intensity for $A_{1g}$, $B_{1g}$ and $B_{2g}$ polarizations, and discuss the peak structures and low-energy power laws which might be expected for several popular models of the superconducting gap in these systems.