RuNMR probe of spin susceptibility in the superconducting state of Sr2RuO4- art. no. 060507

We report Ru-99 Knight-shift (K-99) measurement on the high-quality Sr2RuO4 with a superconducting transition temperature T-c similar to 1.5 K. lts sp in component, K-99(s) due to the core polarization effect caused by Ru-4d s pins, is nearly one order of magnitude larger than that of the O-17 Knight shift (K-17(s)). The 4d-spin susceptibility that has been more precisely me asured from K-99(s) than K-17(s) shows no change across T-c at all. The pre sent result reinforces that Sr2RuO4 is the spin-triplet p-wave superconduct or in which electrons are bound together in parallel-spin pairs parallel to the RuO2 plane.