Abstract
We report detailed nuclear quadrupole resonance investigations of the locally noncentrosymmetric superconductor SrPtAs. The spin-lattice relaxation studies prove weakly coupled multigap superconductivity. A retardation of the decay in evidences a nodeless (fully gapped) superconducting state on the complex multipocket Fermi surface, which is consistent with an anisotropic -wave order parameter and with proposed unconventional -wave and chiral -wave symmetries. A quantitative analysis of these models favors the unconventional -wave state.
- Received 6 January 2014
- Revised 30 October 2014
DOI:https://doi.org/10.1103/PhysRevB.90.220503
©2014 American Physical Society