Hopf-insulator

After the experimental discovery of topological insulators, the notion of what actually constitutes a topological band insulator has been refined in many ways. In their recent work, Aleksandra Nelson, Titus Neupert, Tomáš Bzdušek and Aris Alexandradinata extend the paradigm of topological insulators to areas which were previously thought to contain only trivial insulators.

Being Wannierizable is not the end of the story for topological insulators. We introduce a family of topological insulators that would be considered trivial in the paradigm set by the tenfold way, topological quantum chemistry, and the method of …