In the present study, we investigate a dynamical mode beyond the gyrotropic (G) motion of a magnetic vortex core in a confined magnetic disk of a nano-pillar spin torque nano oscillator. It is characterized by the in-plane circular precession associated to a C-shaped magnetization distribution. We show a transition between G and C-state mode which is found to be purely stochastic in a current-controllable range. Supporting our experimental findings with micromagnetic simulations, we believe that the results provide novel opportunities for the dynamic and stochastic control of STOs, which could be interesting to be implemented for example in neuromorphic networks.
Cite
@article{arxiv.2010.06437,
title = {Beyond the gyrotropic motion: dynamic C-state in vortex spin torque oscillators},
author = {Steffen Wittrock and Philippe Talatchian and Miguel Romera Rabasa and Samh Menshawy and Mafalda Jotta Garcia and Marie-Claire Cyrille and Ricardo Ferreira and Romain Lebrun and Paolo Bortolotti and Ursula Ebels and Julie Grollier and Vincent Cros},
journal= {arXiv preprint arXiv:2010.06437},
year = {2021}
}