Field-Driven Evolution of Chiral Spin Textures in Thin Nanodisk of the   Helimagnets
  The magnetic field-driven evolution of chiral spin textures in thin helimagnet nanodisk with varied size are investigated by means of Monte Carlo simulation. It is demonstrated that the complex spin texture may simply be regarded as the superposition of the edged state with in plane spin orientation perpendicular or parallel to the edge and the bulk state with the features similar to two-dimensional chiral magnetic films. With the increase of the external field, the proportion of the parallel spins of the edge state increases, and the spin textures finally transfers into edged magnetic vortex. The arrangement of skyrmions strongly depends on the disk size. In addition, the uniaxial anisotropy and dipolar coupling in certain ranges are able to stabilize a special magnetic vortex with Skyrmionic core while the disk size is comparable with the wavelength of helix state. 
Haifeng Du, Wei Ning, Mingliang Tian, and Yuheng Zhang
cond-mat.mes-hall