纳米尺度铁磁涡旋的动力学
Dynamics of a nanoscale ferromagnetic vortex
- Korea Advanced Institute of Science and Technology（韩国科学技术院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究提出由iDMI稳定的纳米铁磁涡旋，通过理论分析和微磁模拟证实其在半径小于5 nm的铁磁盘中稳定，兼具微尺度涡旋特性与类杜芬振子等非常规行为，为纳米磁学研究提供新对象。
AI中文摘要：
我们提出一种由界面Dzyaloshinskii-Moriya相互作用（iDMI）稳定的铁磁涡旋，并通过理论分析和微磁模拟研究其特性。结果表明，该涡旋即使在半径小于5 nm的纳米级铁磁盘中也能保持稳定，远小于传统纳米点涡旋约1 μm的半径。我们解析求解了描述非简谐涡旋振荡的非线性运动方程，确定了决定涡旋受驱振荡稳定性的临界频率。这种纳米涡旋具有微尺度涡旋的常规特性，包括陀螺振荡和在垂直磁场下的共振频率偏移；同时还表现出非常规行为，如强非简谐势、非线性振荡以及在外加交流偏置下类杜芬振子的响应。
英文摘要：
We propose a ferromagnetic vortex stabilized by the interfacial Dzyaloshinskii--Moriya interaction (iDMI) and investigate its properties through theoretical analysis and micromagnetic simulations. Our results demonstrate that this vortex can remain stable even in nanoscale ferromagnetic disks with radii below $5\,\text{nm}$---far smaller than those of conventional nanodot vortices having about $1\,μ\text{m}$ radius. We analytically solve the nonlinear equation of motion describing the anharmonic vortex oscillation, and identify the critical frequency that determines the stability of the driven oscillation of the vortex. This nanoscale vortex exhibits conventional properties of microscale vortices, including gyrotropic oscillation and resonance frequency shift under an out-of-plane magnetic field. It also exhibits unconventional behaviors, such as a strongly anharmonic potential, nonlinear oscillations, and a Duffing-oscillator-like response under the external AC bias.
