We report inelastic neutron scattering measurements in the normal state of ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ that reveal the existence of significant incommensurate magnetic spin fluctuations located at ${\mathbf{q}}_0=(\pm 0.6\pi /a,\pm 0.6\pi /a,0\mathrm{})$. This finding confirms recent band-structure calculations that have predicted incommensurate magnetic responses related to dynamical nesting properties of its Fermi surface and points towards the possibility of a competition between $p$-wave spin triplet and $d$-wave spin singlet superconductivity in ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$. We present a comparison between low energy spin fluctuations, converted in absolute units, from inelastic neutron scattering measurements and previous nuclear magnetic resonance studies.

• Received 23 April 1999

DOI:https://doi.org/10.1103/PhysRevLett.83.3320