Abstract
Transverse-field muon-spin rotation measurements in the vortex-lattice of the heavy-fermion (HF) superconductor yield a temperature dependence of the magnetic penetration depth indicative of an isotropic or nearly isotropic energy gap. This is not seen to date in any other HF superconductor and is a signature of isotropic pairing symmetry, possibly related to a novel nonmagnetic “quadrupolar Kondo” HF mechanism in . The relaxation rate yields an estimated magnetic penetration depth , which is considerably shorter than in other HF superconductors.
- Received 18 June 2002
DOI:https://doi.org/10.1103/PhysRevLett.89.157001
©2002 American Physical Society