Magnetic hedgehog lattices in noncentrosymmetric metals
Magnetic hedgehog lattices in noncentrosymmetric metals
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DOI：
10.1103/physrevb.101.144416
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发表时间：
2019-08
影响因子：
3.7
通讯作者：
S. Okumura;S. Hayami;Y. Kato;Y. Motome
中科院分区：
文献类型：
--
作者：
S. Okumura;S. Hayami;Y. Kato;Y. Motome
磁性刺猬晶格（HL）是一种非共面磁性结构，具有周期性的磁单极子和反单极子阵列。尽管迄今为止进行了现象学和数值研究，但微观起源方面仍然存在悬而未决的问题，特别是最近在零磁场下两种不同类型的 HL 的实验结果。在这里，我们研究了有效自旋模型的 HL 稳定性，该模型具有由电子的流动性质引起的长程相互作用。通过变分计算和模拟退火，我们发现，通过自旋轨道耦合产生的反对称交换相互作用和自旋电荷耦合产生的多自旋相互作用的协同效应，HLs在零磁场下稳定在基态。我们还阐明了磁场中的相图，其中包括根据磁场方向单极子和反单极子对湮灭的拓扑相变。
The magnetic hedgehog lattice (HL) is a noncoplanar magnetic texture with a periodic array of magnetic monopoles and anti-monopoles. Despite phenomenological and numerical studies thus far, there remain open issues on the microscopic origin, especially with respect to the recent experimental findings of two different types of HLs even at zero magnetic field. Here, we study the stability of the HLs for an effective spin model with long-range interactions arising from itinerant nature of electrons. By variational calculations and simulated annealing, we find that the HLs are stabilized in the ground state at zero magnetic field by the synergetic effect of the anti-symmetric exchange interactions generated by the spin-orbit coupling and the multiple-spin interactions generated by the spin-charge coupling. We also clarify the phase diagram in the magnetic fields, which includes topological phase transitions with pair annihilation of the monopoles and anti-monopoles depending on the field directions.