Discovering two-dimensional topological insulators from high-throughput computations

This paper presents a comprehensive computational screening for 2D topological insulators based on the Computational 2D Materials Database (https://cmr.fysik.dtu.dk/c2db/c2db.html). More than 3,000 2D materials are investigated using an automated evaluation of the $k$-space Berry phase spectrum, which is calculated directly from the electronic wave functions. The method does not rely on constructing Wannier functions and is therefore ideally suited for high-throughput calculations. A total of 48 quantum spin Hall insulators, seven quantum anomalous Hall insulators, and 21 crystalline topological insulators are identified. A few of the materials have band gaps exceeding 0.5 eV and may constitute promising candidates for realizing topological edge states that are observable at room temperature.