We report the Pb207 nuclear magnetic resonance (NMR) measurements on polycrystalline sample of PbTaSe2 with noncentrosymmetric crystal structure and topological electronic band. The nuclear spin-lattice relaxation rate 1/T1 shows a suppressed coherence peak below the superconducting transition temperature Tc=4.05K and decreases as an exponential function of temperature. The penetration depth derived from the NMR spectrum is almost temperature independent below T=0.7 Tc. The Knight shift K decreases below Tc. These results suggest spin-singlet superconductivity with a fully opened gap 2Δ=3.5kBTc in PbTaSe2.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics