Superconducting pairing in resonant inelastic X-ray scattering

TL;DR

This paper introduces a method to analyze how the superconducting transition influences RIXS signals, revealing unique effects for p-wave order parameters with nodal lines, including a nesting-like phenomenon.

Contribution

A novel quasiparticle-based approach to study the impact of arbitrary symmetry superconducting gaps on RIXS signals, with specific insights into p-wave superconductors.

Findings

The superconducting gap affects RIXS signals differently depending on momentum transfer.

For p-wave with nodal lines, the gap's effect is most prominent along the nodal direction.

The observed phenomenon can be explained as a nesting effect.

Abstract

We develop a method to study the effect of the superconducting transition on resonant inelastic X-ray scattering (RIXS) signal in superconductors with an order parameter with an arbitrary symmetry within a quasiparticle approach. As an example, we compare the direct RIXS signal below and above the superconducting transition for p-wave type order parameters. For a p-wave order parameter with a nodal line, we show that, counterintuitively, the effect of the gap is most noticeable for momentum transfers in the nodal direction. This phenomenon may be naturally explained as a type of nesting effect.