Spin Waves In The Skyrmion Lattice

Magnetic skyrmion can be driven by a very small current and consumes little energy,so it has potential application prospects in future storage and logic devices.First of all,This paper reviews the existence of skyrmion in different magnetic materials: First,skyrmion is greatly affected by the magnetic field and temperature,and the range of its phase region is affected by the geometric shape of magnetic materials.For the temperature-magnetic field phase diagram of the same magnetic material.Second,the skyrmion in different materials is of either Bloch type or Néel type,and the skyrmion structure can be even composed of interesting concentric rings.Antiskyrmion and biskyrmion structure have been observed under certain conditions.These skyrmion have both hexagonal structure and tetragonal structure.Not only two dimensional was observed,but also three-dimensional skyrmion lattice.Thirdly,with the development of research,the problem that skyrmion cannot exist at room temperature is being gradually solved.Then,this paper mainly deduces the effective Hamiltonian in the non-collinear spiral magnetic structure,constructs the low energy effective Hamiltonian excited by the spin wave from the motion equation by using the following motion frame,and obtains the spin wave excitation spectrum in the spiral cone magnetic structure by diagonalization method.Finally,the interaction between the superconducting fluxons and skyrmion is discussed.The conclusions are as follows: First,the total energy decreases with the decrease of the disk size;Second,when the size decreases from 80 nm to 40 nm,the magnetic structure changes from skyrmion structure to single domain structure.Thirdly,the pinning energy is independent of the topological charge of the Skyrmion structure and related to the vertical component of the magnetic moment.