Symmetry plays a crucial role in explorations of the laws of nature. Parity-time (PT) symmetry
phenomena can lead to entirely real spectra in non-Hermitian systems, which attracts …

With the discovery of PT-symmetric quantum mechanics, it was shown that even non-
Hermitian systems may exhibit entirely real eigenvalue spectra. This finding did not only …

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 …

Light propagation in periodic environments is often associated with a number of interesting
and potentially useful processes. If a crystalline optical potential is also linearly ramped, light …

We develop the theory of a special type of scattering state in which a set of asymptotic
channels is chosen as inputs, and the complementary set is chosen as outputs, and there is …

We propose a class of synthetic optical materials in which the refractive index satisfies n (−
x)=− n*(x). We term such systems antisymmetric parity-time (APT) structures. Unlike PT …

We identify a new kind of physically realizable exceptional point (EP) corresponding to
degenerate coherent perfect absorption, in which two purely incoming solutions of the wave …

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 …

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 …

Canonical quantum mechanics postulates Hermitian Hamiltonians to ensure real
eigenvalues. Counterintuitively, a non-Hermitian Hamiltonian, satisfying combined parity …