Multiband superconductivity in PrPt4Ge12 single crystals

Abstract

We report measurements of the London penetration depth $\Delta \lambda (T)$ and the electronic specific heat $C_e(T)$ on high-quality single crystals of the filled-skutterudite superconductor PrPt${}_4$Ge${}_{12}$ ($T_c\simeq$8K). Both quantities show a weak temperature dependence at $T\ll T_c$, following $\Delta \lambda \sim T^n$ ($n\simeq 3.2$) and $C_e/T\sim T^{2.8}$. Such temperature dependences deviate from both conventional s-wave type and nodal superconductivity. A detailed analysis indicates that the superfluid density ${\rho }_s(T)$, derived from the penetration depth, as well as the electronic specific heat can be consistently described in terms of a two-gap model, providing strong evidence of multiband superconductivity for PrPt${}_4$Ge${}_{12}$.

5 pages, 4 figures

References in corpus (5)

• Magnetic Penetration Depth in Unconventional Superconductors
• Superconductivity in the New Platinum Germanides MPt4Ge12 (M = Rare-earth and Alkaline-earth Metals) with Filled Skutterudite Structure
• Superconductivity in novel Ge-based skutterudites: {Sr,Ba}Pt_4Ge_{12}
• Superconducting states in the tetrahedral compound PrOs4Sb12
• Superconducting properties of Pr-based Filled skutterudite PrRu${}_4$As${}_{12}$