Nutation Excitations in the Gyrotropic Vortex Dynamics – consequencies of an additional term in the Landau-Lifshits equation of magnetization motion
Prof. Kostyantyn Gusliyenko, Faculty of Chemistry of the University of the Basque Country UPV/EHU in San Sebastian

Date, Time
09.02, 15:00 - 16:00

Location
Link to MS Teams meeting

A significant activity is devoted to investigation of the ultrafast spin dynamic processes, holding a great potential for science and applications. However, a challenge of the understanding the mechanisms of underlying spin dynamics in nanomaterials at picosecond timescales remains under discussion. In this article, we explore the gyrotropic vortex dynamics in a circular soft magnetic nanodot, highlighting the impacts given by nutations in the high – frequency part of the dot spin excitation spectrum. Using a modified Thiele equation of the vortex core motion with a nutation term, we analyze the dynamic response of the vortex to an oscillating magnetic field. It is found that nutations affect the trajectory of the vortex core. Namely, we show that the directions of the vortex core motion in the low – frequency gyrotropic mode and the high – frequency nutation mode are opposite. The resonant frequencies of gyrotropic and nutational vortex core motions reveal themselves on different scales: GHz for the gyrotropic motion, and THz for the nutations.