The study of classical wave physics has been reinvigorated by incorporating the concept of
the geometric phase, which has its roots in optics, and topological notions that were …

Metamaterials with a Dirac-like cone dispersion at the center of the Brillouin zone behave
like an isotropic and impedance-matched zero refractive index material at the Dirac-point …

The Dirac cone underlies many unique electronic properties of graphene and topological
insulators, and its band structure—two conical bands touching at a single point—has also …

Pseudospin plays a central role in many novel physical properties of graphene and other
artificial systems which have pseudospins of 1/2. Here we show that in certain photonic …

We introduce a class of two-dimensional nonresonant single-phase phononic materials and
investigate its peculiar dispersion characteristics. The material consists of a thin platelike …

Coherent perfect absorption (CPA), as time-reversed lasing, arises from appropriate wave
interference within absorbers, offering flexible control over wave absorption. Typically, this …

It is recognized that for a certain class of periodic photonic crystals, conical dispersion can
be related to a zero-refractive index. It is not obvious whether such a notion can be extended …

Accidental degeneracy plays an important role in the generation of novel band dispersions.
Photonic structures that exhibit an accidental Dirac-like conical dispersion at the center of …

We numerically and experimentally report the acoustic analogue of the super-Klein
tunneling in a heterojunction of phononic crystals formed with Willis scatterers that exhibit …

We propose a mechanism to achieve real energy spectra via Hermitian subspace in non-
Hermitian systems. As an illustrative example, we investigate a system composed of two …