关键词: 涡旋, 交换偏置, 坡莫合金纳米盘, 螺旋运动, 反铁磁

Abstract: The dynamic behavior of the exchanged-biased vortex in permalloy nanodisk was studied by numerical calculations based on the interfacial exchange model we developed. It was found that the frequency of the gyrotropic motion of the vortex core increases linearly with the increasing interfacial exchange constant between ferromagnetic and antiferromagnetic layers under the action of the vortex-shaped pinning field. Meanwhile, the relaxation time required from the vortex core to equilibrium position shortens, thus providing a damping effect on the motion of the vortex core. Then, the trajectory of the vortex core in ferromagnetic layer is no longer a simple helix due to the exchange bias under the action of an external magnetic field, and the distance between vortex core and disk center increases in fluctuation until a stable value happens.