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 …

We aim at providing a global perspective on electromagnetic nonreciprocity and clarifying
confusions that arose in recent developments of the field. We provide a general definition of …

Abstract Parity–time (PT)-symmetric crystals are a class of non-Hermitian systems that allow,
for example, the existence of modes with real propagation constants, for self-orthogonality of …

Recent progress on nonlinear properties of parity-time (PT)-symmetric systems is
comprehensively reviewed in this article. PT symmetry started out in non-Hermitian quantum …

We introduce here the concept of acoustic parity-time (PT) symmetry and demonstrate the
extraordinary scattering characteristics of the acoustic PT medium. On the basis of exact …

Recently, the search for topological states of matter has turned to non-Hermitian systems,
which exhibit a rich variety of unique properties without Hermitian counterparts. Lattices …

Motivated by the demands of integrated and silicon photonics, there is significant interest in
optical isolators in on-chip integrated systems. Recent works have therefore explored …

This tutorial provides an intuitive and concrete description of the phenomena of
electromagnetic nonreciprocity that will be useful for readers with engineering or physics …

One of the challenges of the modern photonics is to develop all‐optical devices enabling
increased speed and energy efficiency for transmitting and processing information on an …

Parity-time (PT) symmetric systems experience phase transition between PT exact and
broken phases at exceptional point. These PT phase transitions contribute significantly to …