Muon spin rotation and relaxation study on topological noncentrosymmetric superconductor PbTaSe2

• Published in: New journal of physics Vol. 24; no. 2; pp. 023002 - 23009
• Main Authors: Zhu, Z H, Tan, C, Zhang, J, Biswas, P K, Hillier, A D, Wang, M X, Yang, Y X, Chen, C S, Ding, Z F, Li, S Y, Shu, L
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.02.2022
• Subjects: Energy gap; Muon spin relaxation; muon spin relaxation/rotation; Muon spin rotation; noncentrosymmetric superconductivity; Physics; Quantum theory; Superconductivity; Symmetry; topological; Topology
• ISSN: 1367-2630
• DOI: 10.1088/1367-2630/ac48ea

Topological superconductivity is an exotic phenomenon due to the symmetry-protected topological surface state, in which a quantum system has an energy gap in the bulk but supports gapless excitations confined to its boundary. Symmetries including central and time-reversal symmetry (TRS), along with their relations with topology, are crucial for topological superconductivity. We report muon spin relaxation/rotation (μSR) experiments on a topological noncentrosymmetric superconductor PbTaSe2 to study its TRS and gap symmetry. Zero-field μSR experiments indicate the absence of internal magnetic field in the superconducting state, consistent with previous μSR results. Furthermore, transverse-field μSR measurements reveals that the superconducting gap of PbTaSe2 is an isotropic three-dimensional fully-gapped single-band. The fully-gapped results can help understand the pairing mechanism and further classify the topological superconductivity in this system.