All-dielectric metamaterials and metasurfaces have been demonstrated as ideal platforms to
manipulate electromagnetic waves and enhance light–matter interaction. Analogous to …

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 …

Recently, exceptional points, a degeneracy of open wave systems, have been observed in
photonics, acoustics, and electronics. They have mainly been realized as a degeneracy of …

Exploiting the interplay between gain, loss and the coupling strength between different
optical components creates a variety of new opportunities in photonics to generate, control …

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 …

In recent years, notions drawn from non-Hermitian physics and parity–time (PT) symmetry
have attracted considerable attention. In particular, the realization that the interplay between …

Non-Hermitian optics is a burgeoning field at the intersection of quantum physics,
electrodynamics, and nanophotonics. It provides a new perspective of the role of gain and …

Nearly one century after the birth of quantum mechanics, parity–time symmetry is
revolutionizing and extending quantum theories to include a unique family of non-Hermitian …

In the past few years, concepts from non-Hermitian (NH) physics, originally developed within
the context of quantum field theories, have been successfully deployed over a wide range of …

Open physical systems can be described by effective non-Hermitian Hamiltonians that
characterize the gain or loss of energy or particle numbers from the system. Experimental …