Topological acoustics is an emerging field that lies at the intersection of condensed matter
physics, mechanical structural design and acoustics engineering. It explores the design and …

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 …

The topological properties of an object, associated with an integer called the topological
invariant, are global features that cannot change continuously but only through abrupt …

The concept of topological energy bands and their manifestations have been demonstrated
in condensed matter systems as a fantastic paradigm toward unprecedented physical …

Modern technological advances allow for the study of systems with additional synthetic
dimensions. Higher-order topological insulators in topological states of matters have been …

The last 20 years have witnessed growing impacts of the topological concept on the
branches of physics, including materials, electronics, photonics, and acoustics. Topology …

Bound state in a continuum (BIC) is a spatially confined resonance with its energy
embedded in a continuous spectrum of propagative modes, yet their coupling is prohibited …

The gain and loss in photonic lattices provide possibilities for many functional phenomena.
In this Letter, we consider photonic topological insulators with different types of gain-loss …

Higher-order topological band theory has transformed the landscape of topological phases
in quantum and classical systems. Here, we experimentally demonstrate a two-dimensional …

We propose a solvable class of 1D quasiperiodic tight-binding models encompassing
extended, localized, and critical phases, separated by nontrivial mobility edges. Limiting …