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 …

The term whispering gallery mode (WGM) was first introduced to describe the curvilinear
propagation of sound waves under a cathedral dome. The physical concept has now been …

BACKGROUND Singularities are critical points for which the behavior of a mathematical
model governing a physical system is of a fundamentally different nature compared to the …

Exceptional points are spectral singularities in open quantum and wave systems that exhibit
a strong spectral response to perturbations. This feature can be exploited for a new …

Exceptional points (EP) are non-Hermitian degeneracies where eigenvalues and their
corresponding eigenvectors coalesce,,–. Recently, EPs have attracted attention as a means …

Exceptional points (EPs) correspond to degeneracies of open systems. These are attracting
much interest in optics, optoelectronics, plasmonics, and condensed matter physics. In the …

Continuous monitoring of intraocular pressure, particularly during sleep, remains a grand
challenge in glaucoma care. Here we introduce a class of smart soft contact lenses …

Non-Hermitian systems, with symmetric or antisymmetric Hamiltonians under the parity-time
(PT) operations, can have entirely real or imaginary eigenvalues. This fact has led to …

Quantum technology has made tremendous strides over the past two decades with
remarkable advances in materials engineering, circuit design, and dynamic operation. In …

Harnessing parity–time symmetry with balanced gain and loss profiles has created a variety
of opportunities in electronics from wireless energy transfer to telemetry sensing and …