Helical spin dynamics in Cu2OSeO3 as measured with small-angle neutron scattering

The insulating chiral magnet Cu2OSeO3 exhibits a rich array of low-temperature magnetic phenomena, making it a prime candidate for the study of its spin dynamics. Using spin wave small-angle neutron scattering (SWSANS), we systematically investigated the temperature-dependent behavior of the helimagnon excitations in the field-polarized phase of Cu2OSeO3. Our measurements, spanning 5-55 K, reveal the temperature evolution of spin-wave stiffness and damping constant with unprecedented resolution, facilitated by the insulating nature of Cu2OSeO3. These findings align with theoretical predictions and resolve discrepancies observed in previous studies, emphasizing the enhanced sensitivity of the SWSANS method. The results provide deeper insights into the fundamental magnetic properties of Cu2OSeO3, contributing to a broader understanding of chiral magnets.