Superconducting gap in BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ from temperature dependent transient optical reflectivity

TL;DR

This study investigates the superconducting gap in BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ using temperature-dependent transient optical reflectivity, revealing a gap consistent with ARPES and insights into optical destruction energy scaling.

Contribution

It provides the first detailed analysis of the superconducting gap and optical destruction energy in BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ using transient reflectivity measurements.

Findings

Superconducting gap of ~5 meV consistent with ARPES results.

Optical destruction energy scales with T$_c^2$.

In-plane optical destruction energy similar across layered superconductors.

Abstract

Temperature and fluence dependence of the 1.55-eV optical transient reflectivity in BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ was measured and analysed in the low and high excitation density limit. The effective magnitude of the superconducting gap of $\sim 5$ meV obtained from the low-fluence-data bottleneck model fit is consistent with the ARPES results for the $\gamma$-hole Fermi surface. The superconducting-state nonthermal optical destruction energy was determined from the fluence dependent data. The in-plane optical destruction energy scales well with T$_{\mathrm{c}}^{2}$ and is found to be similar in a number of different layered superconductors.