ODD-PARITY SUPERCONDUCTIVITY WITH PARALLEL SPIN PAIRING IN UPT3 - EVIDENCE FROM PT-195 KNIGHT-SHIFT STUDY

The temperature dependence of the Pt-195 Knight shift, K, for the high quality single crystal UPt3 has been measured down to T = 28 mK in ap plied magnetic fields parallel and perpendicular to the hexagonal c ax is. No change of K's has been found across the superconducting transit ion temperature T-c down to 28 mK regardless of the crystal directions and independent of the superconducting multiphases. It is demonstrate d that UPt3 is the odd-parity superconductor with parallel spin pairin g following the direction of the magnetic field in a range of 4.4-15.6 kOe without an appreciable pinning of the order parameter to the latt ice.