Raman scattering study of electron-phonon coupling in superconducting LaRu2P2

Abstract

LaRu2P2 shares a similar ThCr2Si2-type structure with iron pnictides and also shows a superconductivity of ∼4 K, but possesses quite different electronic properties. The studies of electronic properties and superconductivity in LaRu2P2 are of particular interest. In this paper, we have conducted a comprehensive Raman scattering study and careful first-principles calculations to explore the electron-phonon coupling (EPC) in LaRu2P2. We have grown very high-quality LaRu2P2 superconducting single crystals with a superconducting transition width ΔTc∼0.15 K. The phonon modes observed in polarized Raman measurements are well assigned with a symmetry analysis. The linewidths of the Raman modes exhibit an anomalous temperature dependence though their Raman frequencies approximately follow the general anharmonic decay process. This allows us to extract the intrinsic phonon broadening caused by EPC, and gives a relatively large EPC constant which is consistent with our first-principles calculations. The estimated Tc∼4.2 K based on the constant suggests a pairing mechanism associated with EPC in LaRu2P2.

Source-reported materials — not catalogue approval

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