Abstract
We report NMR study on a single crystal of the heavy-fermion superconductor without an inversion symmetry along the axis. The Knight-shift measurements under pressure have revealed that the spin susceptibility for the plane decreases slightly below , whereas along the axis it does not change at all. The result can be accounted for by the spin susceptibility in the superconducting state being dominated by the strong antisymmetric (Rashba-type) spin-orbit interaction that originates from the absence of an inversion center along the axis and it being much larger than superconducting condensation energy. This is the first observation which exhibits an anisotropy of the spin susceptibility below in the noncentrosymmetric superconductor dominated by strong Rashba-type spin-orbit interaction.
- Received 9 October 2009
DOI:https://doi.org/10.1103/PhysRevLett.104.017002
©2010 American Physical Society