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 …

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 …

Non-Hermitian degeneracies, also known as exceptional points, have recently emerged as
a new way to engineer the response of open physical systems, that is, those that interact …

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 …

The ideas of topology have found tremendous success in closed physical systems, but even
richer properties exist in the more general open or dissipative framework. We theoretically …

We show that silicon-based metagratings capable of large-angle, multifunctional
performance can be realized using inverse freeform design. These devices consist of …

The bulk-boundary correspondence is crucial to topological insulators. It associates the
existence of boundary states (with zero energy and possessing chiral or helical properties) …

Weyl points are isolated degeneracies in reciprocal space that are monopoles of the Berry
curvature. This topological charge makes them inherently robust to Hermitian perturbations …

Nanophotonics has been an active research field over the past two decades, triggered by
the rising interests in exploring new physics and technologies with light at the nanoscale. As …

Gradient-based inverse design in photonics has already achieved remarkable results in
designing small-footprint, high-performance optical devices. The adjoint variable method …