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arXiv · 0801.4176

Multigap superconductivity in sesquicarbides La$_2$C$_3$ and Y$_2$C$_3$

S. Kuroiwa·Y. Saura·J. Akimitsu·M. Hiraishi·M. Miyazaki·K. H. Satoh·S. Takeshita·R. Kadono
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Abstract

A complex structure of the superconducting order parameter in $Ln_2$C$_3$ ($Ln$ = La, Y) is demonstrated by muon spin relaxation ($μ$SR) measurements in their mixed state. The muon depolarization rate [$σ_{\rm v}(T)$] exhibits a characteristic temperature dependence that can be perfectly described by a phenomenological double-gap model for nodeless superconductivity. While the magnitude of two gaps is similar between La$_2$C$_3$ and Y$_2$C$_3$, a significant difference in the interband coupling between those two cases is clearly observed in the behavior of $σ_{\rm v}(T)$.

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S. Kuroiwa, Y. Saura, J. Akimitsu, M. Hiraishi, M. Miyazaki, K. H. Satoh, S. Takeshita, R. Kadono. 2008-03-07. Multigap superconductivity in sesquicarbides La$_2$C$_3$ and Y$_2$C$_3$. https://doi.org/10.1103/physrevlett.100.097002

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