论文标题
来自四面体磁铁中四旋式手性交换的非统一基态
Non-collinear ground state from a four-spin chiral exchange in a tetrahedral magnet
论文作者
论文摘要
我们提出了一个四分之一的手性术语$ m_x m_y m_z \ nabla \ cdot \ cdot \ mathbf {m} $，用于与平均对称性损坏的立方Ferromagnet的能量密度（点组$ t_d $）。我们证明，这种相互作用导致从共线铁磁状态到非连线磁锥态的相变，前提是其强度超过了磁交换和立方各向异性的几何平均值。相应的非连接基态也可以通过指向某些晶体学方向的外部磁场来稳定。四旋手性交换也确实在特殊的磁子光谱中表现出来，并有利于旋转波的旋转波，其垂直于平均磁化方向。
We propose a quartic chiral term $m_x m_y m_z \nabla \cdot \mathbf{m}$ for the energy density of a cubic ferromagnet with broken parity symmetry (point group $T_d$). We demonstrate that this interaction causes a phase transition from a collinear ferromagnetic state to a non-collinear magnetic cone ground state provided its strength exceeds the geometric mean of magnetic exchange and cubic anisotropy. The corresponding non-collinear ground state may also be additionally stabilized by an external magnetic field pointing along certain crystallographic directions. The four-spin chiral exchange does also manifest itself in peculiar magnon spectra and favors spin waves with the wave vector that is perpendicular to the average magnetization direction.
