Single gap s-wave superconductivity in Nb2PdS5

TL;DR

This study investigates the superconducting gap symmetry in Nb2PdS5, revealing it has a single s-wave gap with a zero-temperature energy gap of 1.05 meV, despite its high upper critical field.

Contribution

The paper provides evidence for single gap s-wave superconductivity in Nb2PdS5, challenging the possible triplet pairing mechanism suggested by its high upper critical field.

Findings

Superconducting gap is best fitted with BCS s-wave model.

Zero-temperature energy gap is estimated at 1.05 meV.

Superfluid density is consistent with a single gap model.

Abstract

Superconducting order parameter and its symmetry are important parameters towards deciphering the pairing mechanism in newly discovered superconducting systems. We report a study on penetration depth measurement on Nb2PdS5 that has recently been reported with extremely high upper critical field with possible triplet pairing mechanism. Our data show that at low temperatures the change in penetration depth is best fitted with BCS s-wave model for single gap. The zero-temperature value of the superconducting energy gap is estimated to be {\Delta}0 = 1.05 meV. The superfluid density in the entire temperature range is well described by single gap for {\lambda} (0) = 220 nm.