Paddison Joseph A M, Rai Binod K, May Andrew F, Calder Stuart, Stone Matthew B, Frontzek Matthias D, Christianson Andrew D
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Savannah River National Laboratory, Aiken, South Carolina, 29808, USA.
Phys Rev Lett. 2022 Sep 23;129(13):137202. doi: 10.1103/PhysRevLett.129.137202.
The experimental realization of magnetic skyrmion crystals in centrosymmetric materials has been driven by theoretical understanding of how a delicate balance of anisotropy and frustration can stabilize topological spin structures in applied magnetic fields. Recently, the centrosymmetric material Gd_{2}PdSi_{3} was shown to host a field-induced skyrmion crystal, but the skyrmion stabilization mechanism remains unclear. Here, we employ neutron-scattering measurements on an isotopically enriched polycrystalline Gd_{2}PdSi_{3} sample to quantify the interactions that drive skyrmion formation. Our analysis reveals spatially extended interactions in triangular planes, and large ferromagnetic interplanar magnetic interactions that are modulated by the Pd/Si superstructure. The skyrmion crystal emerges from a zero-field helical magnetic order with magnetic moments perpendicular to the magnetic propagation vector, indicating that the magnetic dipolar interaction plays a significant role. Our experimental results establish an interaction space that can promote skyrmion formation, facilitating identification and design of centrosymmetric skyrmion materials.
在中心对称材料中实现磁斯格明子晶体的实验是由对各向异性和失稳之间微妙平衡如何在施加磁场中稳定拓扑自旋结构的理论理解所推动的。最近，已证明中心对称材料Gd₂PdSi₃中存在场诱导的斯格明子晶体，但斯格明子的稳定机制仍不清楚。在此，我们对同位素富集的多晶Gd₂PdSi₃样品进行中子散射测量，以量化驱动斯格明子形成的相互作用。我们的分析揭示了三角形平面中的空间扩展相互作用，以及由Pd/Si超结构调制的大的铁磁层间磁相互作用。斯格明子晶体从具有垂直于磁传播矢量的磁矩的零场螺旋磁序中出现，这表明磁偶极相互作用起着重要作用。我们的实验结果建立了一个可促进斯格明子形成的相互作用空间，有助于识别和设计中心对称斯格明子材料。
