As chemists, we are familiar with guidelines and heuristics that help us to predict how chemical reactions will proceed. My group is interested to expand these heuristics to understand if we can predict topological materials. In this talk, I will show that delocalized chemical bonds in certain structural networks allow us to define chemical descriptors that predict whether a material has a band inversion. Using these descriptors, we found several layered, magnetic van der Waals materials, with high carrier mobility. This is the first time that these properties are combined in a single material, which is promising for applications in novel types of data storage or computing devices. We further implemented our heuristics to discover novel complex topological phases, including magnetic ones, and phases that are in competition with complex structural distortions. I will show how structural distortions can have a positive effect on topological band structures. 
 
I will also briefly discuss the concept of chemical exfoliation for the synthesis of novel 2D quantum materials. With this method, we can exfoliate materials for which the scotch tape method fails. I will show how we were able to synthesize a new chromium chalcogenide this way, and discuss advantages and limitations of soft-chemical methods for the synthesis of 2D quantum matter.

To request for meeting link, please write to phweb@ust.hk.