Final Report Summary - TOPOMAT (Topological insulators: computational exploration of emerging electronic materials)
The project explored these novel materials by performing computer simulations at various levels of complexity, ranging from model Hamiltonians to density functional theory and many-body perturbation theory techniques. The global objective is to provide theoretical support required to build a link between the fundamental properties of topological materials and their prospective technological application by investigating physics, chemistry, materials science, and device-related aspects of these materials. This objective was attacked in two different ways – by discovering novel topological materials and by investigating their novel properties and phenomena related to the topological nature.
The most important achievements are the following. First, we developed a methodology that realizes a systematic search of topological materials among known materials. This resulted in the prediction of a large number of candidate compounds, and the most appealing predictions were confirmed experimentally. The prominent examples are the quasi-one-dimensional topological insulator beta-Bi4I4, that is starting an entirely new class of bismuth halide topological materials, and robust Weyl semimetals MoP2 and WP2 that showed an extraordinary combination of physical properties. The discovered material have strong potential towards technological applications. Second, we investigated structure-property relations and the role of disorder in topological insulators. The gained understanding allows to fine-tune the properties of topological materials by changing chemical composition, introducing strain or various defect structures. Importantly, the project has enabled establishing joint activities with experimental research groups worldwide that was crucial for confirming our predictions.