A conventional topological insulator (TI) has gapped bulk states but gapless edge states.
The emergence of the gapless edge states is dictated by the bulk topological invariant of the …

Over the past decade, topology has emerged as a major branch in broad areas of physics,
from atomic lattices to condensed matter. In particular, topology has received significant …

Non-Hermitian systems exhibit striking exceptions from the paradigmatic bulk-boundary
correspondence, including the failure of bulk Bloch band invariants in predicting boundary …

Topological systems are inherently robust to disorder and continuous perturbations,
resulting in dissipation-free edge transport of electrons in quantum solids, or reflectionless …

Recent research in topological photonics has not only proposed and realized novel
topological phenomena such as one‐way broadband propagation and robust transport of …

In the presence of crystalline symmetries, certain topological insulators present a filling
anomaly: a mismatch between the number of electrons in an energy band and the number of …

Recently, higher-order topological phases that do not obey the usual bulk-edge
correspondence principle have been introduced in electronic insulators and brought into …

Certain lattice wave systems in translationally invariant settings have one or more spectral
bands that are strictly flat or independent of momentum in the tight binding approximation …

A d-dimensional second-order topological insulator (SOTI) can host topologically protected
(d-2)-dimensional gapless boundary modes. Here, we show that a 2D non-Hermitian SOTI …

The recently established paradigm of higher-order topological states of matter has shown
that not only edge and surface states, but also states localized to corners, can have robust …