Nonunitary Spin-Triplet Superconductivity in UPt3 : Evidence from 195Pt Knight Shift Study

Tou Hideki

Kitaoka Y.

Ishida K.

Asayama K.

Kimura N.

Ōnuki Y.

Yamamoto E.

Haga Y.

Maezawa K.

Physical review letters

195Pt Knight shift (KS) measurements covering the superconducting multiple phases for major field ( H) orientations have been carried out on the high-quality single crystal UPt3. For H>5 kOe, the KS does not change below the superconducting transition temperature Tc down to 28 mK, regardless of major crystal orientations, which provides evidence that the odd-parity superconductivity with the parallel spin pairing is realized. By contrast, the KS decreases below Tc for Hb∥b axis and Hb<5 kOe and for Hc∥c axis and Hc<2.3 kOe, whereas the KS for Ha∥a axis is T independent across Tc down to Ha∼1.764 kOe. These novel findings entitle UPt3 as the first spin-triplet odd-parity superconductor including a nonunitary pairing characterized by the two-component d vector like db+idc at low T and low H.

Physics [ 420 ]

eng

American Physical Society

Copyright (c) 1998 The American Physical Society

[DOI] http://dx.doi.org/10.1103/PhysRevLett.80.3129 isVersionOf