ABSTRACT
Co/Ru/Co Nanodisks . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 10 .2 .2 Influence of Size on Formation of Skyrmions . . . . . . . 307 10 .2 .3 Influence of an External Magnetic Field on
the Skyrmions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
10 .3 Gyrotropic Motion of the Coupled Skyrmions . . . . . . . . . . . . . . . 310
10 .4 Microwave Field-Driven Resonant Excitations of Coupled Skyrmions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 10 .4 .1 The Effective Mass of Coupled Skyrmions . . . . . . . . . 312 10 .4 .2 Microwave Field Applied to One of the Two
Cobalt Nanolayers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 10 .4 .2 .1 Dual-Frequency Microwave-Driven
Resonant Excitations . . . . . . . . . . . . . . . . . . . . 313 10 .4 .2 .2 Single-Frequency Microwave-Driven
Resonant Excitations . . . . . . . . . . . . . . . . . . . . . . . 318 10 .4 .3 Microwave Field Applied to the Whole
Co/Ru/Co Nanodisk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
10 .5 Current-Driven Resonant Excitations of Coupled Skyrmions . . . 324
10 .6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
A skyrmion, a particle-like topological spin texture where the spins point in all directions covering a whole sphere surface, has nonlocal topological density distribution. When the skyrmion is driven by a magnetic field or a current, the nonlocal topological density distribution may obtain large deformation and lead to novel dynamical behaviors. In this chapter, we investigate the static and dynamical properties of coupled skyrmions obtained in Co/Ru/Co nanodisks, and discuss how the topological density distribution affects the dynamical behaviors.
