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 …

Noise pollution has become a significant global problem in recent years. Unfortunately,
conventional acoustic materials cannot offer substantial improvements in noise reduction …

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 past decades have witnessed the flourishing of non-Hermitian physics in non-
conservative systems, leading to unprecedented phenomena of unidirectional invisibility …

Light and sound are the most ubiquitous forms of waves, associated with a variety of
phenomena and physical effects such as rainbows and echoes. Light and sound, both …

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 …

In active matter systems, individual constituents convert energy into non-conservative forces
or motion at the microscale, leading to morphological features and transport properties that …

Abstract In 1878, Lord Rayleigh observed the highly celebrated phenomenon of sound
waves that creep around the curved gallery of St Paul's Cathedral in London,. These …

Phononic crystals (PCs) and metamaterials (MMs) can exhibit abnormal properties, even far
beyond those found in nature, through artificial design of the topology or ordered structure of …

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