Duffing oscillation-induced reversal of magnetic vortex core by a resonant perpendicular magnetic field

✍ Scribed by Moon, Kyoung-Woong; Chun, Byong Sun; Kim, Wondong; Qiu, Z. Q.; Hwang, Chanyong

• Book ID: 127111603
• Publisher: Springer Science and Business Media LLC
• Year: 2014
• Tongue: English
• Weight: 915 KB
• Volume: 4
• Category: Article
• ISSN: 2045-2322
• DOI: 10.1038/srep06170

✦ Synopsis

Nonlinear dynamics of the magnetic vortex state in a circular nanodisk was studied under a perpendicular alternating magnetic field that excites the radial modes of the magnetic resonance. Here, we show that as the oscillating frequency is swept down from a frequency higher than the eigenfrequency, the amplitude of the radial mode is almost doubled to the amplitude at the fixed resonance frequency. This amplitude has a hysteresis vs. frequency sweeping direction. Our result showed that this phenomenon was due to a Duffing-type nonlinear resonance. Consequently, the amplitude enhancement reduced the vortex core-switching magnetic field to well below 10 mT. A theoretical model corresponding to the Duffing oscillator was developed from the Landau–Lifshitz–Gilbert equation to explore the physical origin of the simulation result. This work provides a new pathway for the switching of the magnetic vortex core polarity in future magnetic storage devices.