The effects of electron correlation and spin-orbit coupling in the isovalent Pd-doped superconductor SrPt$_3$P

TL;DR

This study investigates how electron correlation and spin-orbit coupling influence superconductivity in Pd-doped SrPt$_3$P, revealing a competitive relationship that affects the superconducting transition temperature.

Contribution

It provides the first systematic analysis of the interplay between electron correlation and spin-orbit coupling in Pd-doped SrPt$_3$P superconductors, combining experimental and theoretical approaches.

Findings

Superconducting transition temperature decreases with Pd doping.

Electron susceptibility is suppressed by Pd dopant.

Evidence of competition between spin-orbit coupling and electron correlation.

Abstract

We present a systematical study on the roles of electron correlation and spin-orbit coupling in the isovalent Pd-doped superconductor SrPt$_3$P. By using solid state reaction method, we fabricated the strong spin-orbit coupling superconductors Sr(Pt$_{1-x}$Pd$_x$)$_3$P with strong electron correlated Pd dopant of the $4d$ orbital. As increasing the isovalent Pd concentrations without introducing any extra electron/hole carriers, the superconducting transition temperature $T_c$ decreases monotonously, which suggests the existence of competition between spin-orbit coupling and electron correlation in the superconducting state. In addition, the electronic band structure calculations demonstrate that the strength of electron susceptibility is suppressed gradually by the Pd dopant suggesting the incompatible relation between spin-orbit coupling and electron correlation, which is also consistent with experimental measurements. Our results provide significant insights in the natures of the interplay between the spin-orbit coupling and the electron correlation in superconductivity, and may pave a way for understanding the mechanism of superconductivity in this 5d-metal-based compound.