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Chaotic Dynamics Hamper Reliable Control of Magnetic Vortex Structures

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The stochastic behavior in the formation of vortex structures in asymmetric magnetic nanodisks (Ni80Fe20) was directly imaged with circularly polarized X-rays at Advanced Light Source beamline 6.1.2. The ultrafast dynamics in the initial stage of vortex creation exhibits the characteristics of a butterfly effect; i.e., a chaotic behavior.

Scientific Achievement
X-ray microscopy study showed that ultrafast dynamics in the initial stages of vortex formation plays a dominating role for later stochastic vortex formation in asymmetric magnetic disk arrays.

Significance and Impact
This work provides a deeper fundamental understanding of nanoscale spin behavior and paves the way for potential applications that harness unconventional spin structures.

Research Details

  • Direct observation of vortex structures in asymmetric magnetic disks was performed by the full-field magnetic transmission soft x-ray microscope (ALS Beamline 6.1.2)
  • Simulations demonstrated that ultrafast dynamics in the initial stages of vortex formation can dominate the stochastic behavior observed once the system reaches steady state
  • The study showed the dynamics which triggers the stochasticity in vortex formation exhibits characteristics of a chaotic behavior

M-Y. Im, K.-S. Lee, A. Vogel, J.-I. Hong, G. Meier, P. Fischer, Nature Communications 5 5620 (2014)