论文标题
a $ j _ {\ rm eff} = 1/2 $ kitaev材料三角晶格：naruo $ _2 $的情况
A $j_{\rm eff}=1/2$ Kitaev material on the triangular lattice: The case of NaRuO$_2$
论文作者
论文摘要
由最近在三角形晶格化合物Naruo $ _2 $中的量子失调基态的报道的动机，我们通过第一原则计算得出了该系统的$ j _ {\ rm eff} = 1/2 $磁模型。伪赋量哈密顿量主要取决于债券依赖性的非对角线$γ$相互作用，并以铁磁Heisenberg交换和明显的反铁磁性Kitaev术语进行了补充。除了双线性相互作用外，我们还发现具有强烈各向异性特征的相当大的四旋环交换贡献，在建模Kitaev材料时，它已经被忽略了。磁模型的分析是基于量子哈密顿量的经典能量的最小化和确切的对角线化的，它表明存在相当可靠的易于实现的平面铁磁序，这无法通过物理上相关的扰动轻易地稳定。
Motivated by recent reports of a quantum disordered ground state in the triangular lattice compound NaRuO$_2$, we derive a $j_{\rm eff}=1/2$ magnetic model for this system by means of first-principles calculations. The pseudospin Hamiltonian is dominated by bond-dependent off-diagonal $Γ$ interactions, complemented by a ferromagnetic Heisenberg exchange and a notably antiferromagnetic Kitaev term. In addition to bilinear interactions, we find a sizable four-spin ring exchange contribution with a strongly anisotropic character, which has been so far overlooked when modeling Kitaev materials. The analysis of the magnetic model, based on the minimization of the classical energy and exact diagonalization of the quantum Hamiltonian, points toward the existence of a rather robust easy-plane ferromagnetic order, which cannot be easily destabilized by physically relevant perturbations.
