论文标题
高厅电导率，符号变化在海森伯格 - 基塔维·凯戈姆磁铁中
Thermal Hall conductivity with sign change in the Heisenberg-Kitaev kagome magnet
论文作者
论文摘要
各种晶格上的海森堡 - 基塔夫（HK）模型引起了很多关注，因为它们可能导致异国情调的状态，例如量子自旋液体和拓扑秩序。基于稀有的千年的kagome晶格（KL）化合物$ \ rm {mg_2re_3sb_3o_ {14}} $ $ $ \ rm {（re = gd，er）} $和$ \ rm {（re = nd）} $ （CFM）分别订单。有趣的是，KL上的HK模型具有相同的基态远程订单。在理论相图中，CFM相位在连续参数区域中，并且在特殊参数点之间没有相变的相变，例如Kitaev Ferromagnetic（KFM）点，铁磁（FM）点及其双FM点。但是，基态性能无法区分有或没有拓扑非平凡激发和相关相变的系统。在这里，我们研究了具有CFM顺序的HK模型中HK模型中的拓扑镁激发和相关的热门电导率。 CFM阶段可以分为两个由klein二元性相关的区域，而自二键KFM则是其边界。我们发现，CFM顺序中固有的标量自旋手性改变了整个KFM点的符号。这导致了两个区域中相应少量带的相应的Chern数量，也导致了磁棒热棒电导率的符号变化。
The Heisenberg-Kitaev (HK) model on various lattices have attracted a lot of attention because they may lead to exotic states such as quantum spin liquid and topological orders. The rare-earth-based kagome lattice (KL) compounds $\rm{Mg_2RE_3Sb_3O_{14}}$ $\rm{(RE=Gd, Er)}$ and $\rm{(RE=Nd)}$ have ${\bf q=0}$, $120^\circ$ order and canted ferromagnetic (CFM) order, respectively. Interestingly, the HK model on the KL has the same ground state long-range orders. In the theoretical phase diagram, the CFM phase resides in a continuous parameter region and there is no phase change across special parameter points, such as the Kitaev ferromagnetic (KFM) point, the ferromagnetic (FM) point and its dual FM point. However, a ground state property cannot distinguish a system with or without topological nontrivial excitations and related phase transitions. Here, we study the topological magnon excitations and related thermal Hall conductivity in the HK model on the KL with CFM order. The CFM phase can be divided into two regions related by the Klein duality, with the self dual KFM point as their boundary. We find that the scalar spin chirality which is intrinsic in the CFM order changes sign across the KFM point. This leads to the opposite Chern numbers of corresponding magnon bands in the two regions, and also the sign change of the magnon thermal Hall conductivity.
