Max Planck Institute of Microstructure Physics, Halle, Germany.
Department of Condensed Matter Physics, University of the Basque Country UPV/EHU, Bilbao, Spain.
Nature. 2020 Oct;586(7831):702-707. doi: 10.1038/s41586-020-2837-0. Epub 2020 Oct 28.
The discoveries of intrinsically magnetic topological materials, including semimetals with a large anomalous Hall effect and axion insulators, have directed fundamental research in solid-state materials. Topological quantum chemistry has enabled the understanding of and the search for paramagnetic topological materials. Using magnetic topological indices obtained from magnetic topological quantum chemistry (MTQC), here we perform a high-throughput search for magnetic topological materials based on first-principles calculations. We use as our starting point the Magnetic Materials Database on the Bilbao Crystallographic Server, which contains more than 549 magnetic compounds with magnetic structures deduced from neutron-scattering experiments, and identify 130 enforced semimetals (for which the band crossings are implied by symmetry eigenvalues), and topological insulators. For each compound, we perform complete electronic structure calculations, which include complete topological phase diagrams using different values of the Hubbard potential. Using a custom code to find the magnetic co-representations of all bands in all magnetic space groups, we generate data to be fed into the algorithm of MTQC to determine the topology of each magnetic material. Several of these materials display previously unknown topological phases, including symmetry-indicated magnetic semimetals, three-dimensional anomalous Hall insulators and higher-order magnetic semimetals. We analyse topological trends in the materials under varying interactions: 60 per cent of the 130 topological materials have topologies sensitive to interactions, and the others have stable topologies under varying interactions. We provide a materials database for future experimental studies and open-source code for diagnosing topologies of magnetic materials.
具有大反常霍尔效应的半导体和轴子绝缘体等本征磁性拓扑材料的发现,推动了固态材料的基础研究。拓扑量子化学使人们能够理解和寻找顺磁拓扑材料。利用从磁拓扑量子化学(MTQC)中获得的磁拓扑指数,我们基于第一性原理计算对磁拓扑材料进行了高通量搜索。我们以毕尔巴鄂晶体学服务器上的磁材料数据库为起点,该数据库包含超过 549 种具有从中子散射实验推断出的磁结构的磁性化合物,并确定了 130 种强制半导体(其能带交叉由对称本征值暗示)和拓扑绝缘体。对于每个化合物,我们都进行了完整的电子结构计算,其中包括使用不同 Hubbard 势值的完整拓扑相图。我们使用自定义代码找到所有磁性空间群中所有能带的磁共表示,生成数据输入到 MTQC 算法中,以确定每个磁性材料的拓扑结构。其中一些材料显示了以前未知的拓扑相,包括由对称性表示的磁性半导体、三维反常霍尔绝缘体和更高阶磁性半导体。我们分析了材料在不同相互作用下的拓扑趋势:130 种拓扑材料中有 60%的拓扑结构对相互作用敏感,其余的拓扑结构在不同相互作用下是稳定的。我们提供了一个材料数据库,供未来的实验研究和用于诊断磁性材料拓扑结构的开源代码使用。