Superconducting gap structure of BaFe_2(As_{1-x}P_{x})_2

TL;DR

This study investigates the superconducting gap structure in BaFe2(As1-xPx)2, revealing the presence and location of nodes on all Fermi surface sheets through specific heat measurements.

Contribution

It provides detailed experimental evidence on the nodal structure and its Fermi surface location in BaFe2(As1-xPx)2, advancing understanding of its superconducting properties.

Findings

Nodes are located in the [110] directions.

Nodes exist on all Fermi surface sheets.

Specific heat measurements reveal the gap structure.

Abstract

We present a study of the superconducting gap structure in the iron-pnictide series BaFe2(As1-xPx)2. By measuring the variation of the specific heat as a function of temperature and magnetic field we are able to determine the number and Fermi surface location of the nodes in the superconducting gap. In particular, from measurements of the variation of the specific heat as the magnetic field is rotated in the ab plane of the sample we conclude that the nodes are in the [110] directions. Then from a quantitative analysis of the temperature and field dependence of the specific heat we further conclude that nodes exists on all Fermi surface sheets.