Lithographically defined arrays of nanomagnets are well placed for application in areas such as probabilistic computing or reconfigurable magnonics due to their emergent collective dynamics and writable magnetic order. Among them are artificial spin ice (ASI), which are arrays of binary in-plane macrospins exhibiting geometric frustration at the vertex interfaces. Macrospin flips in the arrays create topologically protected magnetic charges, or emergent monopoles, which are bound to an antimonopole to conserve charge. In the absence of controllable pinning, it is difficult to manipulate individual monopoles in the array without also influencing other monopole excitations or the counter-monopole charge. Here, we tailor the local magnetic order of a classic ASI lattice by introducing a ferromagnetic defect with shape anisotropy into the array. This creates monopole injection sites at nucleation fields below the critical lattice switching field. Once formed, the high energy monopoles are fixed to the defect site and may controllably propagate through the lattice under stimulation. Defect programing of bound monopoles within the array allows fine control of the pathways of inverted macrospins. Such control is a necessary prerequisite for the realization of functional devices, e. g. reconfigurable waveguide in nanomagnonic applications.

由于其涌现的集体动力学和可写磁序，光刻定义的纳米磁体阵列非常适合应用于概率计算或可重构磁子学等领域。其中包括人工自旋冰 (ASI)，它是二元平面内宏自旋的阵列，在顶点界面处表现出几何挫折。阵列中的宏观自旋翻转产生受拓扑保护的磁荷或涌现单极子，它们与反单极子结合以保存电荷。在没有可控钉扎的情况下，很难在不影响其他单极子激发或反单极子电荷的情况下操纵阵列中的单个单极子。在这里，我们通过在阵列中引入具有形状各向异性的铁磁缺陷来定制经典 ASI 晶格的局部磁序。这会在临界晶格转换场下方的成核场处创建单极子注入位点。一旦形成，高能单极子就被固定到缺陷位置，并且可以在刺激下可控地传播通过晶格。阵列内束缚单极子的缺陷编程允许精细控制倒置宏观自旋的路径。这种控制是实现功能器件的必要先决条件，例如纳米磁应用中的可重构波导。