论文标题
Skyrmion托管中心对称四方磁体的广泛扫描磁场 - 温度相图
Widely-sweeping magnetic field-temperature phase diagrams for skyrmion-hosting centrosymmetric tetragonal magnets
论文作者
论文摘要
我们在热波动和巡回中心对称四方磁铁中的热波动和外部磁场下进行数值研究的稳定机制。通过采用较小的计算成本的有效陡峭下降方法，我们系统地构建了二维平方晶格上源自巡回电子模型的有效自旋模型的磁场 - 温度相图。结果，我们发现平方型的天际晶体通过高谐波波形相互作用和外部磁场下的两种相互作用来稳定。尤其是，我们发现以前的高谐波波形相互作用只能在其幅度较小时在有限温度下稳定天空晶体。除了Skyrmion晶体外，我们还在相图中找到了其他稳定的多重Q $状态。最后，我们讨论了有效的旋转模型与Skyrmion-Bonosting Material GDRU $ _2 $ SI $ _2 $之间的相位图的对应关系。目前的结果表明，各种多重Q $状态可能是由中心对称巡回磁铁中的热波动和外部磁场驱动的。
We numerically investigate the stabilization mechanisms of skyrmion crystals under thermal fluctuations and external magnetic field in itinerant centrosymmetric tetragonal magnets. By adopting an efficient steepest descent method with a small computational cost, we systematically construct the magnetic field-temperature phase diagrams of the effective spin model derived from the itinerant electron model on a two-dimensional square lattice. As a result, we find that a square-type skyrmion crystal is stabilized by either or both of the high-harmonic wave-vector interaction and the biquadratic interaction under an external magnetic field. Especially, we discover that the former high-harmonic wave-vector interaction can stabilize the skyrmion crystal only at finite temperatures when its magnitude is small. In addition to the skyrmion crystal, we also find other stable multiple-$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.
