Normal-state spin dynamics in the spin-triplet superconductor Sr2RuO4 - art. no. 100501

Magnetic properties in the normal state of spin-triplet superconductor Sr2R uO4 are discussed on the basis of Ru- and O-NMR and neutron-diffraction (ND ) measurements reported so far. Besides strong incommensurate antiferromagn etic (IC-AFM) fluctuations probed by the ND measurements, it is shown that q-independent fluctuations are present over a wide temperature range up to 500 K from the comparison between NMR and ND results. From an anisotropy in the nuclear spin lattice relaxation rate 1/T-1 at both the Ru and O sites, it was found that the IC-AFM fluctuations are anisotropic so that the out- of-plane component of low-frequency dynamical susceptibility, chi'(IC,out)( q,omega) is by a factor of similar to3 larger than the in-plane one, chi"(I C,in)(q, omega). These unique characters in magnetic fluctuations are impli ed to have some relevance for the occurrence of spin-triplet superconductiv ity.