Probing the superconducting pairing of the La4Be33Pt16alloy via muon-spin spectroscopy

Tian Shang; Eteri Svanidze; Toni Shiroka

doi:10.1088/1361-648X/ad0e93

Probing the superconducting pairing of the La₄Be₃₃Pt₁₆alloy via muon-spin spectroscopy

J Phys Condens Matter. 2023 Dec 1;36(10). doi: 10.1088/1361-648X/ad0e93.

Authors

Tian Shang^{1

2}, Eteri Svanidze³, Toni Shiroka^{4

5}

Affiliations

¹ Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China.
² Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing 401120, People's Republic of China.
³ Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
⁴ Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
⁵ Laboratorium für Festkörperphysik, ETH-Hönggerberg, CH-8093 Zürich, Switzerland.

PMID: 37988753
DOI: 10.1088/1361-648X/ad0e93

Abstract

We report a study of the superconducting pairing of the noncentrosymmetric La₄Be₃₃Pt₁₆alloy using muon-spin rotation and relaxation (µSR) technique. BelowTc=2.4 K, La₄Be₃₃Pt₁₆exhibits bulk superconductivity (SC), here characterized by heat-capacity and magnetic-susceptibility measurements. The temperature dependence of the superfluid densityρsc(T), extracted from the transverse-fieldµSR measurements, reveals a nodeless SC in La₄Be₃₃Pt₁₆. The best fit ofρsc(T)using ans-wave model yields a magnetic penetration depthλ0=542 nm and a superconducting gapΔ0=0.37 meV at zero Kelvin. The single-gapped superconducting state is further evidenced by the temperature-dependent electronic specific heatCe(T)/Tand the linear field-dependent electronic specific-heat coefficientγH(H). The zero-fieldµSR spectra collected in the normal- and superconducting states of La₄Be₃₃Pt₁₆are almost identical, confirming the absence of an additional field-related relaxation and, thus, of spontaneous magnetic fields belowT_c. The nodeless SC combined with a preserved time-reversal symmetry in the superconducting state proves that the spin-singlet pairing is dominant in La₄Be₃₃Pt₁₆. This material represents yet another example of a complex system showing only a conventional behavior, in spite of a noncentrosymmetric structure and a sizeable spin-orbit coupling.

Keywords: fully-gapped superconductivity; muon-spin rotation and relaxation; noncentrosymmetric superconductor.