A vortex molecule is predicted in a spin–orbit-coupled spin-1 Bose–Einstein condensate. This type of asymmetric soliton features four off-axis vortices and none of them coincide. There are two vortices of the same charge in the first and the third component, respectively, and two vortices of the opposite charge in the second component. This particular arrangement of vortices constitute a spin vortex molecule which is connected by a domain wall in the spin texture. In the dynamical simulation, we find the vortex molecule is static at the equilibrium but vibrates once it deviates from the equilibrium. The vibration mechanism is identified: fragmentation and coalescence. The vortex molecule exhibits mixing of ferromagnetic and antiferromagnetic states, where the meron-pair or bimeron is hidden. Our results suggest a way of creating bimeron-like vortex molecules in spin-1 Bose–Einstein condensates.

中文翻译：

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自旋-轨道耦合 spin-1 凝聚态中的涡旋分子


在自旋-轨道耦合-自旋-1 玻色-爱因斯坦凝聚态中预测涡旋分子。这种类型的不对称孤子具有四个离轴涡旋，它们都不重合。第一分量和第三分量中分别有两个相同电荷的漩涡，第二分量中有两个相反电荷的漩涡。这种特殊的涡旋排列构成了一个自旋涡旋分子，它由自旋织构中的畴壁连接。在动力学仿真中，我们发现涡流分子在平衡状态下是静态的，但一旦偏离平衡状态就会振动。确定了振动机制：碎裂和聚结。涡旋分子表现出铁磁态和反铁磁态的混合，其中 meron 对或 bimeron 被隐藏。我们的结果提出了一种在自旋 1 玻色-爱因斯坦凝聚态中创建 bimeron 样涡旋分子的方法。