发表机构
Qom University of Technology; University of Toronto; Shahrekord University（库姆理工大学; 多伦多大学; 沙赫里克尔德大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过扩展J1-K-Γ-Γ'-J2-J3模型，结合Luttinger-Tisza方法与精确对角化，揭示了BaCo2(AsO4)2中非公度螺旋相源于远邻交换受挫与键各向异性的协同作用，而非Kitaev耦合主导，并阐明了其量子竞争机制。
AI 中文摘要
在蜂窝状钴酸盐$\mathrm{BaCo}_2(\mathrm{AsO}_4)_2$中，零场非公度磁有序的微观机制仍是一个重要的未解问题，特别是关于键方向Kitaev型相互作用与交换受挫的相对贡献。本研究探讨了一个扩展的$J_1\text{--}K\text{--}\Gamma\text{--}\Gamma'\text{--}J_2\text{--}J_3$模型，该模型在蜂窝晶格上包含了XXZ型交换各向异性。最近邻参数由从头算电子结构计算约束。通过将解析的Luttinger-Tisza方法与扭曲边界条件下的精确对角化计算相结合，我们描绘了$(J_2, J_3)$参数空间中的经典和量子相图。我们证明，实验观察到的沿$\Gamma\to M$方向传播的非公度螺旋相的稳定并不需要异常占主导的Kitaev耦合。相反，该相自然产生于由远邻耦合（$J_2, J_3$）驱动的交换受挫与中间非对角键各向异性（$\Gamma, \Gamma'$）之间的协同相互作用。在量子区域，我们阐明了该非公度流形与面外铁磁（$\mathrm{FM}_z$）相之间的竞争，后者通过量子序由无序机制被选择性地稳定。我们的发现调和了关于$\mathrm{BaCo}_2(\mathrm{AsO}_4)_2$中磁相互作用相互矛盾的解释，并确立了其非公度基态的微观起源和稳定范围。
英文摘要
The microscopic mechanism governing the zero-field incommensurate magnetic order in the honeycomb cobaltate $\mathrm{BaCo}_2(\mathrm{AsO}_4)_2$ remains a significant unresolved problem, particularly concerning the relative contributions of bond-directional Kitaev-type interactions and exchange frustration. This study investigates an extended $J_1\text{--}K\text{--}Γ\text{--}Γ'\text{--}J_2\text{--}J_3$ model, which incorporates XXZ-type exchange anisotropies on the honeycomb lattice. Nearest-neighbor parameters are constrained by ab initio electronic structure calculations. By integrating the analytical Luttinger-Tisza approach with exact diagonalization calculations under twisted boundary conditions, we delineate the classical and quantum phase diagrams across the $(J_2, J_3)$ parameter space. We demonstrate that the stabilization of the experimentally observed incommensurate spiral phase, propagating along the $Γ\to M$ direction, does not necessitate an anomalously dominant Kitaev coupling. Instead, this phase arises naturally from the synergistic interplay between exchange frustration, driven by further-neighbor couplings ($J_2, J_3$), and intermediate off-diagonal bond anisotropies ($Γ, Γ'$). In the quantum regime, we elucidate the competition between this incommensurate manifold and an out-of-plane ferromagnetic ($\mathrm{FM}_z$) phase, which is selectively stabilized via a quantum order-by-disorder mechanism. Our findings reconcile conflicting interpretations of the magnetic interactions in $\mathrm{BaCo}_2(\mathrm{AsO}_4)_2$ and establish the microscopic origin and stability range of its incommensurate ground state.
Comments11 pages, 5 figures
