Symmetry-enforced topological band crossings in orthorhombic crystals: Classification and materials discovery
Andreas Leonhardt, Moritz M. Hirschmann, Niclas Heinsdorf, Xianxin Wu, Douglas H. Fabini, Andreas P. Schnyder
Abstract
Topological semimetals are highly sought after for their unusual functional properties. The symmetries of a space group can guarantee the existence of band degeneracies with nontrivial topology in its band structures. In this article, the authors list all symmetry enforced band degeneracies in the orthorhombic space groups for spinless band structures, as well as spinful band structures with non-negligible spin-orbit coupling. To connect the results of the symmetry analysis with real materials, criteria for a systematic search in large material databases are introduced and used to provide real material examples for some of the most interesting topological features.