Topological Nature of Edge States for One-Dimensional Systems without Symmetry Protection

Author(s): Janet Zhong, Heming Wang, Alexander N. Poddubny, and Shanhui Fan We numerically verify and analytically prove a winding number invariant that correctly predicts the number of edge states in one-dimensional, nearest-neighbor (between unit cells), two-band models with any complex couplings and open boundaries. Our winding number uses analytical continuation of the … [Phys. Rev. Lett. 135, 016601] Published Mon Jun 30, 2025