Indirect switching of vortex polarity through magnetic dynamic coupling

Dynamic origin of vortex core switching in soft magnetic nanodots.

The magnetic vortex with in-plane curling magnetization and out-of-plane magnetization at the core is a unique ground state in nanoscale magnetic elements. This kind of magnetic vortex can be used, through its downward or upward core orientation, as a memory unit for information storage, and thus, controllable core switching deserves some special attention. Our analytical and micromagnetic calc...

Vortex polarity switching in magnets with surface anisotropy

Vortex core reversal in magnetic particle is essentially influenced by a surface anisotropy. Under the action of a perpendicular static magnetic field the vortex core undergoes a shape deformation of pillowor barrel-shaped type, depending on the type of the surface anisotropy. This deformation plays a key point in the switching mechanism: We predict that the vortex polarity switching is accompa...

Vortex polarity switching by a spin-polarized current.

The spin-transfer effect is investigated for the vortex state of a magnetic nanodot. A spin current is shown to act similarly to an effective magnetic field perpendicular to the nanodot. Then a vortex with magnetization (polarity) parallel to the current polarization is energetically favorable. Following a simple energy analysis and using direct spin-lattice simulations, we predict the polarity...

Axial-symmetric Vortex Polarity Switching in Ferromagnetic Particles

Switching phenomena in magnetic vortex dynamics

A magnetic nanoparticle in a vortex state is a promising candidate for the information storage. One bit of information corresponds to the upward or downward magnetization of the vortex core (vortex polarity). Generic properties of the vortex polarity switching are insensitive of the way how the vortex dynamics was excited: by an ac magnetic field, or by an electrical current. We study theoretic...