Magnon dispersion in ferromagnetic SrRuO3

The magnetic excitations in ferromagnetic SrRuO3 were studied by inelastic neutron scattering combining experiments on triple-axis and time-of-flight spectrometers with and without polarization analysis. A quadratic spin-wave dispersion with an anisotropy gap describes the low-energy low-temperature response. The magnon dispersion extends to at least 35 meV and there is no direct evidence for a continuum of Stoner excitations below this energy. However, the magnon response is weakened at higher energy. In addition to the anomalous softening of the spin-wave stiffness and of the gap, which is induced by the topology of the Bloch states, the magnon excitations are broadened in energy and this effect increases upon heating.

Automated summary

The magnetic excitations in ferromagnetic SrRuO3 were investigated using inelastic neutron scattering experiments on triple-axis and time-of-flight spectrometers. The low-energy low-temperature response exhibited a quadratic spin-wave dispersion with an anisotropy gap. The magnon dispersion extended up to 35 meV, with no evidence of a continuum of Stoner excitations below this energy. However, the magnon response weakened at higher energies. In addition to the anomalous softening of the spin-wave stiffness and gap induced by the topology of the Bloch states, the magnon excitations also showed broadening in energy, which increased with temperature.