论文标题
洪德的耦合辅助铁磁渗透渗透性过渡
Hund's coupling-assisted ferromagnetic percolation transition in a multiorbital flat band
论文作者
论文摘要
通过将Hund的物理学与平坦的频带物理联系起来，我们为研究多功能系统中的铁磁磁性建立了一个确切的结果。我们考虑了一个两层型号，该型号由$ p_x $，$ p_y $ - 轨道蜂窝晶格层和$ f $ - 轨道三角形晶格层，该层与蜂窝状plaquettes中心对齐的站点。该系统具有平坦的频带，该频带允许两层之间适当的化学势差的渗透表示。在此表示中，基态空间由局部单粒子状态的最大旋转簇跨越，并且在基态上平均会导致由于群集的自旋变性而引起的重量与权重相关。如蒙特卡罗模拟所示，随着频带接近半填充，传感磁性铁磁过渡会发生，而基态则被大的最大旋转群集所主导。
By connecting Hund's physics with flat band physics, we establish an exact result for studying ferromagnetism in a multiorbital system. We consider a two-layer model consisting of a $p_x$, $p_y$-orbital honeycomb lattice layer and an $f$-orbital triangular lattice layer with sites aligned with the centers of the honeycomb plaquettes. The system features a flat band that admits a percolation representation for an appropriate chemical potential difference between the two layers. In this representation, the ground state space is spanned by maximum-spin clusters of localized single-particle states, and averaging over the ground states yields a correlated percolation problem with weights due to the spin degeneracy of the clusters. A paramagnetic-ferromagnetic transition occurs as the band approaches half filling and the ground states become dominated by states with a large maximum-spin cluster, as shown by Monte Carlo simulation.
