论文标题
相关性如何改变Kagome Hubbard模型的磁性结构因子
How correlations change the magnetic structure factor of the kagome Hubbard model
论文作者
论文摘要
Kagome Hubbard模型（KHM）是沮丧的二维模型的范式示例。虽然其强烈的相关状态（由海森堡模型描述，由于其神秘的前瞻性旋转基态基态而引起了人们的兴趣，但弱和中等相关的方案在很大程度上仍未探索。由迅速增加的金属kagome材料（例如Mn $ _3 $ sn，fe $ _3 $ _3 $ _3 $ sn $ _2 $，FESN，CO $ _3 $ _3 $ sn $ sn $ _2 $ _2 $ _2 $，GD $ _3 $ _3 $ _3 $ _3 $ _3 $ _4 $ _4 $ al $ al $ _ $ _ {12} $），我们的含义：动态平均场理论（DMFT），动力学顶点近似（D $γ$ A）和行列式量子蒙特卡洛（DQMC）。与原型平方晶格相反，我们发现磁相关性保持短距离，我们没有发现磁性排序的趋势。然而，随着系统接近金属对绝缘体的跃迁，磁相关经历了显着的跨界。但是，莫特过渡本身不会影响磁相关。我们的相等和动力学结构因子可以用作对金属kagome材料不断增长的家族的非弹性中子散射实验的参考。
The kagome Hubbard model (KHM) is a paradigmatic example of a frustrated two-dimensional model. While its strongly correlated regime, described by a Heisenberg model, is of topical interest due to its enigmatic prospective spin-liquid ground state, the weakly and moderately correlated regimes remain largely unexplored. Motivated by the rapidly growing number of metallic kagome materials (e.g., Mn$_3$Sn, Fe$_3$Sn$_2$, FeSn, Co$_3$Sn$_2$S$_2$, Gd$_3$Ru$_4$Al$_{12}$), we study the respective regimes of the KHM by means of three complementary numerical methods: the dynamical mean-field theory (DMFT), the dynamical vertex approximation (D$Γ$A), and determinant quantum Monte Carlo (DQMC). In contrast to the archetypal square-lattice, we find no tendencies towards magnetic ordering, as magnetic correlations remain short-range. Nevertheless, the magnetic correlations undergo a remarkable crossover as the system approaches the metal-to-insulator transition. The Mott transition itself does however not affect the magnetic correlations. Our equal-time and dynamical structure factors can be used as a reference for inelastic neutron scattering experiments on the growing family of metallic kagome materials.
