Bosonic spectrum of a correlated multiband system, BaFe1.80Co0.20As2, obtained via infrared spectroscopy

TL;DR

This study uses infrared spectroscopy to analyze the bosonic spectrum of Co-doped BaFe2As2, revealing key superconducting properties and differences from K-doped variants, aiding understanding of superconductivity in these materials.

Contribution

First detailed infrared spectroscopic analysis of bosonic spectrum in Co-doped BaFe2As2, providing insights into its superconducting characteristics and differences from K-doped counterparts.

Findings

Extracted bosonic spectrum and superconducting parameters.

Identified differences between Co- and K-doped Ba122.

Provided data useful for superconductivity understanding and applications.

Abstract

We investigated a single crystal BaFe(2-x)CoxAs2 (Co-doped BaFe2As2: Co-doped Ba122) with x = 0.20 using infrared spectroscopy. We obtained the bosonic spectrum from the measured spectrum using an extended Drude-Lorentz model for the normal state and a two-parallel-channel approach for the superconducting (SC) state, based on the generalized Allen formula. The coupling constant, maximum SC transition temperature, SC coherence length, and upper critical field were extracted from the bosonic spectrum. The superfluid plasma frequency and the London penetration depth were obtained from the optical conductivity. We compared the physical quantities of Co-doped Ba122 and K-doped Ba122 and found some interesting differences. Our results may be helpful for understanding superconductivity in doped Ba122 systems and may provide useful information on doped Ba122 systems for their applications.