论文标题
带有通用交换各向异性的Kagome磁铁的订购基态
Ordered ground states of kagome magnets with generic exchange anisotropy
论文作者
论文摘要
越来越多的稀土kagome材料家族具有主要的最近邻邻，旋转轨道耦合。这些材料的低对称性使理论描述变得复杂，允许六个不同的最近的邻居偶联参数。在本文中，我们询问，假设一系列通用（即非固定）的交换参数集，则可以预期在这些材料中发生哪些经典，有序的基态。我们使用对称分析表明，通用参数只有五个不同的经典基态阶段。这五个阶段是：（i）一个堕落2倍的共面，带有消失的磁化（$ {\ sf a_1} $），（ii）一个非稳态，2倍变性的状态，具有磁化速度为磁性，垂直于Kagome Plane（$ {\ sf a_2} $），（\ sf a_2} $），（ii ii ii ii i coplan） within the kagome plane (${\sf E}$-coplanar), (iv) a noncoplanar, 6-fold degenerate, state with magnetization lying within a mirror plane of the lattice (${\sf E}$-noncoplanar$_{6}$), (v) a noncoplanar, 12-fold degenerate, state with magnetization in an arbitrary direction （$ {\ sf e} $ - noncoplanar $ _ {12} $）。所有五个都是翻译不变的（$ {\ bf q} = 0 $）状态。找到了一组可能的接地状态后，可以通过比较每种可能性作为耦合参数的函数的数值优化能量来获得基态相图。状态$ {\ sf e} $ noncoplanar $ _ {12} $极为罕见，占据了整个相图的$ <1 \％$，因此，就实际目的而言，有四个主要有序状态可能发生在各向异性Kagome磁铁中，具有主要的最近邻居相互作用。这些结果可以帮助解释``tripod kagome''系统的最新实验r $ _3 $ _2 $ _2 $ sb $ _3 $ _3 $ o $ _ {14} $，以及更接近cr-和fe-jarosite等各向异性极限的材料。
There is a growing family of rare-earth kagome materials with dominant nearest-neighbor interactions and strong spin orbit coupling. The low symmetry of these materials makes theoretical description complicated, with six distinct nearest-neighbor coupling parameters allowed. In this Article, we ask what kinds of classical, ordered, ground states can be expected to occur in these materials, assuming generic (i.e. non-fine-tuned) sets of exchange parameters. We use symmetry analysis to show that there are only five distinct classical ground state phases occurring for generic parameters. The five phases are: (i) a coplanar, 2-fold degenerate, state with vanishing magnetization (${\sf A_1}$), (ii) a noncoplanar, 2-fold degenerate, state with magnetization perpendicular to the kagome plane (${\sf A_2}$), (iii) a coplanar, 6-fold degenerate, state with magnetization lying within the kagome plane (${\sf E}$-coplanar), (iv) a noncoplanar, 6-fold degenerate, state with magnetization lying within a mirror plane of the lattice (${\sf E}$-noncoplanar$_{6}$), (v) a noncoplanar, 12-fold degenerate, state with magnetization in an arbitrary direction (${\sf E}$-noncoplanar$_{12}$). All five are translation invariant (${\bf q}=0$) states. Having found the set of possible ground states, the ground state phase diagram is obtained by comparing numerically optimized energies for each possibility as a function of the coupling parameters. The state ${\sf E}$ noncoplanar$_{12}$ is extremely rare, occupying $<1\%$ of the full phase diagram, so for practical purposes there are four main ordered states likely to occur in anisotropic kagome magnets with dominant nearest neighbor interactions. These results can aid in interpreting recent experiments on ``tripod kagome'' systems R$_3$A$_2$Sb$_3$O$_{14}$, as well as materials closer to the isotropic limit such as Cr- and Fe- jarosites.
