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 …

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 …

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 …

In the past decade, the concept of parity-time $(\mathcal {PT}) $ symmetry, originally
introduced in non-Hermitian extensions of quantum mechanical theories, has come into …

A short résumé is given about the nature of exceptional points (EPs) followed by discussions
about their ubiquitous occurrence in a great variety of physical problems. EPs feature in …

Parity-time (PT) symmetric periodic structures, near the spontaneous PT-symmetry breaking
point, can act as unidirectional invisible media. In this regime, the reflection from one end is …

In a recent work, YD Chong [Phys. Rev. Lett. 105, 053901 (2010)] 0031-9007
10.1103/PhysRevLett. 105.053901 proposed the idea of a coherent perfect absorber (CPA) …

We show both theoretically and experimentally that a pair of inductively coupled active LRC
circuits (dimer), one with amplification and another with an equivalent amount of attenuation …

The fermion doubling theorem plays a pivotal role in Hermitian topological materials. It
states, for example, that Weyl points must come in pairs in three-dimensional semimetals …

When a planar dielectric medium has a permittivity profile that is an analytic function in the
upper or lower half of the complex position plane x= x′+ ix ″then the real and imaginary …