论文标题
磁性天空
Magnetic skyrmions under confinement
论文作者
论文摘要
我们提出了在与交换能量竞争的界面dzylashinksii-moriya相互作用（DMI）的超薄铁磁性膜的最小微磁模型中的差异处理，并可能添加垂直磁性磁性。在Dirichlet边界条件下，是由在薄膜限制中渐近处理杂散场能进行的，我们证明存在拓扑非平凡的能量最小化器，这些能量最小化集中在域中的点上，因为DMI强度参数倾向于零。此外，我们在消失的DMI强度极限的$γ$扩展中得出了领先的非平凡项，这使我们能够完全表征有限的磁化磁化特征并将其解释为粒子状的状态，其半径和位置是通过将重新授权的能量功能最小化来确定的。特别是，我们表明，在我们的环境中，天空是从域边界中强烈排斥的，这使它们具有稳定性，这对于应用程序非常可取。我们为许多基本域几何形状提供了重新归一化的能量的明确计算。
We present a variational treatment of confined magnetic skyrmions in a minimal micromagnetic model of ultrathin ferromagnetic films with interfacial Dzylashinksii-Moriya interaction (DMI) in competition with the exchange energy, with a possible addition of perpendicular magnetic anisotropy. Under Dirichlet boundary conditions that are motivated by the asymptotic treatment of the stray field energy in the thin film limit we prove existence of topologically non-trivial energy minimizers that concentrate on points in the domain as the DMI strength parameter tends to zero. Furthermore, we derive the leading order non-trivial term in the $Γ$-expansion of the energy in the limit of vanishing DMI strength that allows us to completely characterize the limiting magnetization profiles and interpret them as particle-like states whose radius and position are determined by minimizing a renormalized energy functional. In particular, we show that in our setting the skyrmions are strongly repelled from the domain boundaries, which imparts them with stability that is highly desirable for applications. We provide explicit calculations of the renormalized energy for a number of basic domain geometries.
