An exciton can be described as an electron-hole pair in a crystal that is bound in a manner analogous to the electron and proton in a hydrogen atom. The exciton behaves like an atomic excitation that passes from one atom to another. In most cases, excitons are induced by an electromagnetic wave, a photon. Interestingly […]
Some materials have special universal properties protected against perturbations. Such properties are theoretically described by topology, a branch of mathematics concerned with the properties of geometrical objects that are unchanged by continuous deformations. So-called topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have conducting states on their […]
When the surface of a perfect conductor is structured at a length scale much smaller than the operating wavelength, geometrically induced surface electromagnetic modes can be supported. Owing to their similarities with the surface plasmon polaritons in the optical regime, these surface electromagnetic modes were named spoof surface plasmons. A new review provides a detailed […]
CFM • DIPC • DIPC Photonics
Usually, optical activity is understood as the ability some substances have to change the handedness of polarized light when it goes through them. Molecules that show optical activity have no plane of symmetry. So-called chiral matter broadly describes structures for which left- or right-handed mirror images are non-superimposable, or, equivalently, that lack improper rotation axes […]
Some materials have special universal properties protected against perturbations. Such properties are theoretically described by topology, a branch of mathematics concerned with the properties of geometrical objects that are unchanged by continuous deformations. So-called topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have conducting states on their […]
An exciton can be described as an electron-hole pair in a crystal that is bound in a manner analogous to the electron and proton in a hydrogen atom. Thus, the exciton behaves like an atomic excitation that passes from one atom to another. Exciton energy states involve a band with a particular dispersion law that […]
CFM • DIPC • DIPC Photonics
Plasmonic cavities formed by metallic surfaces are nanostructures that confine light to dimensions far smaller than the free-space wavelength, as they mix optical fields with electronic excitations. I t was not until the 1990s, with the appearance of accurate and reliable nanofabrication techniques, that plasmonics blossomed. It was found then that local fields around nanostructures […]
A nanoantenna with balanced electric and magnetic dipole moments exhibits a directive radiation pattern with zero backscattering. This is known as the first Kerker condition after Kerker, Wang, and Giles, who predicted in 1983 that, under plane wave illumination, magnetic spheres with equal relative permittivity and permeability radiate no light in the backscattering direction. They […]
The so-called van der Waals materials consist of two-dimensional layers bound by weak van der Waals forces. After the isolation of graphene, the field of two-dimensional van der Waals materials has experienced an explosive growth and new families of two-dimensional systems and block-layered bulk materials have been created. This growth has been fuelled mainly by […]
A nanoantenna with balanced electric and magnetic dipole moments exhibits a directive radiation pattern with zero backscattering. This is known as the first Kerker condition after Kerker, Wang, and Giles, who predicted in 1983 that, under plane wave illumination, magnetic spheres with equal relative permittivity and permeability radiate no light in the backscattering direction. They […]