We review quantum mechanical and optical pseudo-Hermitian systems with an emphasis on
PT-symmetric systems important for optics and electrodynamics. One of the most interesting …

This chapter introduces the basic ideas of P T-symmetric systems. It begins with a brief
discussion of closed (isolated) and open (non-isolated) systems and explains that P T …

We introduce here a parity-time-(PT) symmetric system using an optically pumped, active
graphene metasurface paired with a resistive metallic filament, realizing a unidirectional …

Spontaneous symmetry breaking is a source of the phase transition in a variety of physical
systems including such as non-Hermitian. It has recently been demonstrated that so-called …

We investigate here active metasurfaces obeying parity–time (PT) symmetry and their
sensing applications, taking advantage of singularities unique to non-Hermitian systems …

Recent developments in non-Hermitian physics offer exciting opportunities for a broad range
of basic research and engineering applications relevant to the antennas and propagation …

Planar junctions between reactive surface impedances with dual character
(capacitive/inductive) can sustain line waves localized both in-plane and out-of-plane …

Bound states in the continuum (BICs) are peculiar discrete states embedded in the
continuous spectrum. It has been reported that BICs still exist and exhibit new features when …

We address the properties of fully three-dimensional solitons in complex parity-time (PT)-
symmetric periodic lattices with focusing Kerr nonlinearity, and uncover that such lattices can …

Achieving exact balance between spatially separated gain and loss is generally regarded as
a necessary condition for parity-time-(PT-) symmetric optical systems. We introduce …