Superconducting gap structure of the skutterudite LaPt4Ge12 probed by specific heat and thermal transport

TL;DR

This study investigates the superconducting gap structure of LaPt4Ge12 using specific heat and thermal transport measurements, finding evidence for a single s-wave gap but considering possible multiband effects, and comparing it with related compounds.

Contribution

The paper provides detailed experimental analysis of LaPt4Ge12's superconducting gap, suggesting a single s-wave symmetry and discussing its relation to other skutterudites, which advances understanding of their pairing mechanisms.

Findings

Data compatible with a single s-wave gap

Multiband scenario cannot be ruled out

Order parameters similar for LaPt4Ge12 and PrPt4Ge12

Abstract

We investigated the superconducting order parameter of the filled skutterudite LaPt4Ge12, with a transition temperature of Tc = 8.3 K. To this end, we performed temperature and magnetic-field dependent specific-heat and thermal-conductivity measurements. All data are compatible with a single superconducting s-wave gap. However, a multiband scenario cannot be ruled out. The results are discussed in the context of previous studies on the substitution series Pr1-xLaxPt4Ge12. They suggest compatible order parameters for the two end compounds LaPt4Ge12 and PrPt4Ge12. This is not consistent with a single s-wave gap in LaPt4Ge12 considering previous reports of unconventional and/or multiband superconductivity in PrPt4Ge12.