Widely-sweeping magnetic field?temperature phase diagrams for skyrmion-hosting centrosymmetric tetragonal magnets
Widely-sweeping magnetic field?temperature phase diagrams for skyrmion-hosting centrosymmetric tetragonal magnets
复制标题
斯格明子中心对称四方磁体的宽扫磁场温度相图
DOI：
10.1016/j.jmmm.2023.170547
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发表时间：
2023
影响因子：
2.7
通讯作者：
Kato Yasuyuki
中科院分区：
文献类型：
--
作者：
Hayami Satoru;Kato Yasuyuki
数值研究了巡回中心对称四方磁体中Skyrmion晶体在热涨落和外加磁场作用下的稳定机制。采用计算代价小、效率高的最速下降法，系统地构造了二维正方形晶格上由巡游电子模型导出的有效自旋模型的磁场-温度相图。结果表明，在外加磁场作用下，四方型Skyrmion晶体可以被高次谐波波矢相互作用和双二次相互作用中的一种或两种稳定。特别是，我们发现原来的高次谐波波-矢量相互作用只能在有限温度下稳定Skyrmion晶体，当它的量级很小时。除了Skyrmion晶体外，我们还在相图中发现了其他稳定的多Q态。最后，我们讨论了有效自旋模型与天空离子托管材料GDRU2Si2之间的相图的对应关系。结果表明，中心对称巡回磁体中的热涨落和外加磁场可以驱动多种多Q态。
We numerically investigate the stabilization mechanisms of skyrmion crystals under thermal fluctuations and external magnetic field in itinerant centrosymmetric tetragonal magnets. By adopting an efficient steepest descent method with a small computational cost, we systematically construct the magnetic field–temperature phase diagrams of the effective spin model derived from the itinerant electron model on a two-dimensional square lattice. As a result, we find that a square-type skyrmion crystal is stabilized by either or both of the high-harmonic wave–vector interaction and the biquadratic interaction under an external magnetic field. Especially, we discover that the former high-harmonic wave–vector interaction can stabilize the skyrmion crystal only at finite temperatures when its magnitude is small. In addition to the skyrmion crystal, we also find other stable multiple-Q states in the phase diagram. Lastly, we discuss the correspondence of the phase diagrams between the effective spin model and the skyrmion-hosting material GdRu 2 Si 2. The present results suggest a variety of multiple-Q states could be driven by thermal fluctuations and external magnetic fields in centrosymmetric itinerant magnets.