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 …

The past decades have witnessed an explosion of interest in topological materials, and a lot
of mathematical concepts have been introduced in condensed matter physics. Among them …

Non-Hermitian theory is a theoretical framework used to describe open systems. It offers a
powerful tool in the characterization of both the intrinsic degrees of freedom of a system and …

There are two prominent applications of the mathematical concept of topology to the physics
of materials: band topology, which classifies different topological insulators and semimetals …

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 …

Superconductivity has been observed in moiré systems such as twisted bilayer graphene,
which host flat, dispersionless electronic bands. In parallel, theory work has discovered that …

Diffusion driven by temperature or concentration gradients is a fundamental mechanism of
energy and mass transport that inherently differs from wave propagation in both physical …

A review is given on the foundations and applications of non-Hermitian classical and
quantum physics. First, key theorems and central concepts in non-Hermitian linear algebra …

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 …