Anomalous gapped boundaries between surface topological orders in higher-order topological insulators and superconductors with inversion symmetry

Ming-Hao Li, Titus Neupert, S. A. Parameswaran +1

We show that the gapless boundary signatures - namely, chiral/helical hinge modes or localized zero modes - of three-dimensional higher-order topological insulators and superconduc…