Noncollinear magnetism opens exciting possibilities to generate topological superconductivity. Here, we focus on helical and cycloidal magnetic textures in magnet-superconductor hybrid structures in a background magnetic field. We demonstrate that this system can enter a topological phase which can be understood as a set of parallel topological wires. We explore and confirm this idea in depth with three different approaches: a continuum model, a tight-binding model based on the magnetic unit cell, and exact diagonalization on a finite two-dimensional lattice. The key signature of this topological state is the presence of Majorana bound states at certain disclination defects in the magnetic texture. Based on the $C_2$ symmetry imposed by the helical or cycloidal texture, we employ the theory of topological crystalline superconductors with rotation invariants to obtain the Majorana parity at disclinations. Furthermore, we consider a 90-deg helimagnet domain wall, which is formed by a string of alternating disclinations. We discuss how the resulting chain of disclination bound states hybridizes into two chiral modes with different velocities. We suggest that hybrid systems of chiral magnets and superconductors are capable of hosting Majorana modes in various spatial configurations with potentially far less nanoengineering than in, e.g., semiconductor wires.

中文翻译：

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螺旋和摆线磁体-超导体混合体的出线相中的Majorana模式

非共线磁性为产生拓扑超导性提供了令人兴奋的可能性。在这里，我们专注于背景磁场中磁体-超导体混合结构中的螺旋和摆线磁性纹理。我们证明了该系统可以进入拓扑阶段，该阶段可以理解为一组平行的拓扑线。我们用三种不同的方法深入探讨并确认了这种想法：连续模型，基于磁性晶胞的紧密结合模型以及有限二维晶格上的精确对角化。该拓扑状态的关键特征是在磁织构的某些向错缺陷处存在马约拉纳键态。基于$C_2$由于螺旋或摆线结构具有对称性，我们采用具有旋转不变性的拓扑晶体超导体理论来获得旋错处的马约拉纳奇偶性。此外，我们考虑了由一连串交替的向错形成的90度倾斜磁畴壁。我们讨论了错位结合态的结果链如何杂交成两种具有不同速度的手性模式。我们建议，手性磁体和超导体的混合系统能够以各种空间构型承载马约拉那模式，而纳米工程的潜力可能远小于例如半导体线材。