Probing higher-order topology in density wave insulators
Motivated by recent experimental work on (TaSe_4)_2I and bismuth halides, I will discuss how band topology can be influenced and engineered via density wave distortions. Through a series of simple examples in two and three dimensions, I will show how the sliding mode in topological charge- and spin-density wave materials offers a new avenue to access nontrivial topological phases and to probe topological response functions. I will further show how techniques such as topological quantum chemistry can explain the pumping of bulk and edge states in these systems, both with and without time-reversal symmetry. Finally, I will show how our results offer a promising route to understanding topological phases in incommensurate systems.
Host: Jen Cano