Metamaterials are artificially engineered periodic structures with exceptional optical properties that are not found in conventional materials. They are built from individual elements, designed to mimic the electromagnetic response of atoms. Stacking many nano-engineered elements smaller than the wavelength of light makes new solid materials. Such materials have extremely unusual properties, such as negative refractive indices to focus light much smaller than its wavelength (super-lensing), or electromagnetic cloaking (of an object). The alliance of metamaterials with the fields of plasmonics, nanophotonics and nanofabrication technologies can further advance the possibility of controlling light propagation, radiation, localization and scattering in in unprecedented ways.
A multigate transistor, refers to a metal–oxide–semiconductor field-effect transistor that incorporates more than one gate into a single device. The multiple gates may be controlled by a single gate electrode, wherein the multiple gate surfaces act electrically as a single gate, or by independent gate electrodes. A multigate device employing independent gate electrodes is sometimes called a multiple-independent-gate field-effect transistor. The most widely used multi-gate devices are the FinFET (fin field-effect transistor) and the GAAFET (gate-all-around field-effect transistor), which are non-planar or 3D transistors.
In photodetectors, incident photons interact with the electrons in the material and change the electronic charge distribution. This perturbation of the charge distribution generates a current or a voltage that can be measured by an electrical circuit. Standard quantum-well infrared photodetectors are based on single-bound state quantum wells, and electronic transitions between such bound state and the continuum are used for photon detection. Incident photons excite bound electrons into the continuum contributing to what is called the photocurrent, which is the detection signal measured by such devices. The well width and composition, and thus the depth of the bound state, are designed to match with the energy of the photons to be detected.
The spaser is a nano plasmonic counterpart of the laser. The spasing modes are surface plasmons whose localization length is on the nanoscale. The resonator for spasing can be specially designed plasmonic metal nanostructures. This resonator should be surrounded by the gain medium that overlaps with the spasing SP eigenmode spatially and whose emission line overlaps with this eigenmode spectrally.
Mie–Gans theory optically characterizes ellipsoidal and by extension generally elongated nonchiral metal nanoparticles (MNPs) and is ubiquitous in verifying experimental results and predicting particle behavior. Recently, elongated chiral MNPs have garnered enthusiasm, but a theory to characterize their chiroptical behavior is lacking in the literature. In this Letter, we present an ab initio model for… Read More »Chiral Plasmonic Ellipsoids: An Extended Mie–Gans Model.