论文标题
二维偶极海森贝格模型的相图具有dzyaloshinskii-moriya相互作用和伊索各向异性
Phase diagram of the two-dimensional dipolar Heisenberg model with the Dzyaloshinskii-Moriya interaction and the Ising anisotropy
论文作者
论文摘要
我们研究了二维海森堡模型中的相变，该模型与dzyaloshinskii-moriya相互作用，伊索各向异性（$η$）以及在零和有限磁场下的偶性相互作用（$ h $）。对于偶极相互作用的三个典型优势（零，弱和强），我们通过使用$ O（n）$ algorithm的蒙特卡洛方法来估算Skyrmion-lattice和Helical阶段的订单参数，并介绍$ h $ - $η$相图。我们在相图中发现了三种类型的天际晶格阶段，即两个正方形的晶格和一个三角形晶格，具有对角线和垂直（或水平）条纹的螺旋相，倾斜的铁磁相和极化的铁磁相。偶极相互作用的效果以复杂的方式变化了天际和螺旋相的类型。偶极相互作用还扩大了伴随相边界向正$ h $和$η$方向移动的有序阶段的区域，并导致天空密度的增加以及螺旋结构的音高长度（条纹宽度）的缩短。我们讨论相变特征的细节。
We study phase transitions in the two-dimensional Heisenberg model with the Dzyaloshinskii-Moriya interaction, the Ising anisotropy ($η$), and the dipolar interaction under zero and finite magnetic fields ($H$). For three typical strengths (zero, weak, and strong) of the dipolar interaction, we present the $H$-$η$ phase diagrams by estimating order parameters for skyrmion-lattice and helical phases and in-plane magnetization by using a Monte Carlo method with an $O(N)$ algorithm. We find in the phase diagrams three types of skyrmion-lattice phases, i.e., two square lattices and a triangular lattice, helical phases with diagonal and vertical (or horizontal) stripes, canted ferromagnetic phase and polarized ferromagnetic phase. The effect of the dipolar interaction varies the types of the skyrmion and helical phases in a complex manner. The dipolar interaction also expands the regions of the ordered phases accompanying shifts of the phase boundaries to the positive $H$ and $η$ directions, and causes increase of the density of skyrmions and shortening of the pitch length (stripe width) of helical structures. We discuss the details of the features of the phase transitions.
