Superconducting gap structure in carrier doped BiCh2-based layered superconductors: A μSR study. (November 2022)

• Record Type: Journal Article
• Authors: Bhattacharyya, A.; Adroja, D.T.; Sogabe, R.; Goto, Y.; Mizuguchi, Y.; Hillier, A.D.
• Is Part Of: Journal of physics and chemistry of solids. Volume 170(2022)
• Publication Date: 2022-11
• Subjects: Layered bismuth oxy-sulfide materials -- Muon spin rotation -- Multigap superconductivity -- Pairing symmetry; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2022.110898
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: The layered bismuth oxy-sulfide materials, which are structurally similar to Fe-pnictides/chalcogenides and cuprates superconductors, have sparked a lot of interest in the physics of reduced-dimensional superconductors. The pairing symmetry of the recently discovered BiCh 2 -based superconductor, La 1−x Ce x OBiSSe with x = 0.3, was investigated using zero-field and transverse field (TF) muon spin measurements, as well as using magnetization and resistivity measurements. Resistivity and magnetization data confirmed bulk superconductivity below 2.7 K for x = 0.3. The temperature dependence of the magnetic penetration depth has been determined from TF- μ SR data, which can be described by an isotropic two-gap s + s wave model compared to a single gap s - or anisotropic s -wave model, which resembles with Fe-pnictides/chalcogenides and MgB 2 . Furthermore, from the TF- μ SR data, we have determined the London's penetration depth λ L ( 0 ) = 452(3) nm, superconducting carrier's density n s = 2.18(1) × 10 26 carriers/m 3 and effective mass enhancement m ∗ = 1.66(1) m e, respectively. No signature of spontaneous internal field is found down to 100 mK in ZF- μ SR measurement, which suggests that time-reversal symmetry is preserved in this system. Highlights: Layered bismuth oxy-sulfide materials, reduced-dimensional superconductors. Superconducting pairing symmetry using ZF-, TF- μ SR. Bulk superconductivity below 2.7 K for x = 0 . 3 . Multigap s + s wave superconductivity. Preserved time-reversal symmetry.