Dynamics of the antiferromagnetic skyrmion induced by a magnetic anisotropy gradient

The dynamics of antiferromagnets is a current hot topic in condensed matter\nphysics and spintronics. However, the dynamics of insulating antiferromagnets\ncannot be excited by an electric current, which is a method usually used to\nmanipulate ferromagnetic metals. Here, we propose to use the voltage-controlled\nmagnetic anisotropy gradient as an excitation source to manipulate insulating\nantiferromagnetic textures. We analytically and numerically study the dynamics\nof an antiferromagnetic skyrmion driven by a magnetic anisotropy gradient. Our\nanalytical calculations demonstrate that such a magnetic anisotropy gradient\ncan effectively drive an antiferromagnetic skyrmion towards the area of lower\nmagnetic anisotropy. The micromagnetic simulations are in good agreement with\nour analytical solution. Furthermore, the magnetic anisotropy gradient induced\nvelocity of an antiferromagnetic skyrmion is compared with that of a\nferromagnetic skyrmion. Our results are useful for the understanding of\nantiferromagnetic skyrmion dynamics and may open a new way for the design of\nantiferromagnetic spintronic devices.\n