论文标题
从头算的“ Kitaev”材料Baco $ _2 $（ASO $ _4 $）$ _ 2 $的最低模型的最低模型：直接跳跃，第三个邻近交换和量子波动的重要性
Ab initio guided minimal model for the "Kitaev" material BaCo$_2$(AsO$_4$)$_2$: Importance of direct hopping, third-neighbor exchange and quantum fluctuations
论文作者
论文摘要
通过考虑两种基于基于}的互补方法，我们分析了电子结构并提取Baco $ _2 $（ASO $ _4 $）$ _ 2 $的有效自旋模型，这是一种蜂窝材料，该材料已提议作为Kitaev物理学的候选者。这两种方法都表明，主要的直接跳跃使键依赖的基塔夫术语可忽略不计，从而使材料远离了受欢迎的自旋液体状态。结果，我们提出了一个简单的三参数交换模型，以描述蜂窝架的最低双线baco $ _2 $（ASO $ _4 $）$ _ 2 $的相互作用。值得注意的是，这是各向同性和各向异性的第三次互动，负责由BACO $ _2 $（ASO $ _4 $）$ _ 2 $的出色双Zigzag地面状态稳定在量子波动中。在{\ it i ab in obizus}中观察到的一个明显的第三名最大的邻居跳跃支持了第三邻居相互作用在稳定的Baco $ _2 $（ASO $ _4 $）$ _ 2 $的稳定中的重要性。
By considering two {\it ab initio}-based complementary approaches, we analyze the electronic structure and extract effective spin models of BaCo$_2$(AsO$_4$)$_2$, a honeycomb material which has been proposed as a candidate for Kitaev physics. Both methods show that the dominant direct hopping makes the bond-dependent Kitaev term negligible averting the material away from the sought-after spin-liquid regime. As a result, we present a simple three-parameter exchange model to describe the interactions of the lowest doublet of the honeycomb cobaltate BaCo$_2$(AsO$_4$)$_2$. Remarkably, it is the third-neighbor interactions, both isotropic and anisotropic, that are responsible for the standout double-zigzag ground state of BaCo$_2$(AsO$_4$)$_2$, stabilized by quantum fluctuations. A significantly large third-nearest neighbor hopping, observed in {\it ab initio}, supports the importance of the third-neighbor interactions in the stabilization of the unique ground state of BaCo$_2$(AsO$_4$)$_2$.
