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arXiv · 2010.06437

Beyond the gyrotropic motion: dynamic C-state in vortex spin torque oscillators

Steffen Wittrock·Philippe Talatchian·Miguel Romera Rabasa·Samh Menshawy·Mafalda Jotta Garcia·Marie-Claire Cyrille·Ricardo Ferreira·Romain Lebrun·Paolo Bortolotti·Ursula Ebels·Julie Grollier·Vincent Cros
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Abstract

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.

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Steffen Wittrock, Philippe Talatchian, Miguel Romera Rabasa, Samh Menshawy, Mafalda Jotta Garcia, Marie-Claire Cyrille, Ricardo Ferreira, Romain Lebrun, Paolo Bortolotti, Ursula Ebels, Julie Grollier, Vincent Cros. 2020-10-11. Beyond the gyrotropic motion: dynamic C-state in vortex spin torque oscillators. https://doi.org/10.1063/5.0029083

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