Computational search for magnetic topological materials in Eu compounds*

Topological materials are of great interests for both basic research and future technology. Recent developments of symmetry indicators and similar approaches to diagnose band structure topology have resulted in databases of non-magnetic topological materials via high throughput band structure calculations. However, magnetic topological materials have been much less explored. One of the reasons is that the magnetic ground state structures are not readily available like crystallography databases and also different magnetic configurations can be competing in energy. But this also offers the opportunity to use magnetism to control topological properties of materials. Here we have explored Eu compounds using band structure calculations based on density functional theory and found several Eu compounds can host ferromagnetic Weyl, anti-ferromagnetic Dirac as well as anti-ferromagnetic topological insulating states depending on different magnetic configurations.