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

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 …

Additive manufacturing (AM), particularly Selective Laser Melting (SLM) has enabled
development of lattice structures with unique properties. Through control of various …

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 …

Acoustic metamaterials can manipulate and control sound waves in ways that are not
possible in conventional materials. Metamaterials with zero, or even negative, refractive …

The coupling of waves between the piezoelectric generators, detectors, and propagating
media is challenging due to mismatch in the acoustic properties. The mismatch leads to the …

Within a time span of 15 years, acoustic metamaterials have emerged from academic
curiosity to become an active field driven by scientific discoveries and diverse application …

Broadband sound sink/absorber via a structure with deep sub-wavelength thickness is of
great and continuing interest in physics and engineering communities. An intuitive technique …

Manipulating the properties of the isofrequency contours (IFCs) of materials provides a
powerful means of controlling the interaction between light and matter. Hyperbolic …

The introduction of engineered resonance phenomena on surfaces has opened a new
frontier in surface science and technology. Pillared phononic crystals, metamaterials, and …