'Parabolic' trapped modes and steered Dirac cones in platonic crystals.

Numerical investigation of the flat band Bloch modes in a 2D photonic crystal with Dirac cones.

A numerical method combining complex-k band calculations and absorbing boundary conditions for Bloch waves is presented. We use this method to study photonic crystals with Dirac cones. We demonstrate that the photonic crystal behaves as a zero-index medium when excited at normal incidence, but that the zero-index behavior is lost at oblique incidence due to excitation of modes on the flat band....

Topology-optimized dual-polarization Dirac cones

We apply a large-scale computational technique, known as topology optimization, to the inverse design of photonic Dirac cones. In particular, we report on a variety of photonic crystal geometries, realizable in simple isotropic dielectric materials, which exhibit dual-polarization Dirac cones. We present photonic crystals of different symmetry types, such as fourfold and sixfold rotational symm...

Investigation of Variations of Isotropic g- and A- Values with Orientation of Trapped O2−, N2− and Cl2− Radicals in KCl and NaCl Crystals

Creating and Manipulating Electron Beams in Graphene

An electron collimator composed of a point-like source and a parabolic pn junction is proposed as a generator of highly focused electron beams in graphene. The collimator is based on negative refraction and Klein collimation, which are unique to pseudo-relativistic Dirac materials. The electron beams generated by the lensing apparatus can be steered by a weak magnetic field without losing colli...

Plexciton Dirac points and topological modes

Plexcitons are polaritonic modes that result from the strong coupling between excitons and plasmons. Here, we consider plexcitons emerging from the interaction of excitons in an organic molecular layer with surface plasmons in a metallic film. We predict the emergence of Dirac cones in the two-dimensional band-structure of plexcitons due to the inherent alignment of the excitonic transitions in...