In this paper, the properties of the defect mode in the photonic band gap ofone-dimensional ternary photonic crystals containing high temperature superconductorlayer (SPCs) have been theoretically investigated. We considered the quasi-periodiclayered structures by choosing two order of ternary Thue-Morse structures with mirrorsymmetry. We investigated the transmission spectra of these structure...

SiO2/ZnS core/shell nanostructures have been synthesized at room temperature by a simple wet chemical method. The prepared materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR), UV–vis spectroscopic and transmission electron microscopy (TEM) studies. X-ray diffraction pattern exhibits peaks correspond to the cubic phase of ZnS. Th...

Magneto-transmission measurements were carried out on a series of ZnMnSe/ZnBeSe quantum wells (QWs) in order to determine the band o!set of ZnBeSe relative to ZnSe. We observed strong transitions from the ground state of the valence band to that of the conduction band in this system. The transition energy was observed to systematically increase with increasing Be concentration in the ZnBeSe bar...

The stabilities and electronic/band structures of single-layer bismuth oxyhalides have been investigated by employing first-principles calculations. The results indicate that the single-layer bismuth oxyhalide materials, except for BiOF, have robust energetic and dynamical stabilities because of their low formation energies and the absence of imaginary frequencies within the entire Brillouin zo...

The structure and the electronic properties of single-walled zigzag BN and B3C2N3 nanotubes (n, 0; n=4–10) were investigated using first-principles calculations based on a density functional theory. A plane–wave basis set with periodic boundary conditions in conjunction with Vanderbilt ultrasoft pseudo-potential was employed. The energy gap of ZB3C<su...

The report "Optical studies of hydrogen above 200 gigapascals: Evidence for metallization by band overlap" by H. K. Mao and R. J. Hemley (1) in my opinion does not present evidence that conclusively demonstrates the metallization mentioned in the title. The most demanding test of such metallization is to show that the dc electrical conductivity remains finite as the temperature goes to zero. On...

Materials and structures that strongly discriminate electromagnetic radiation based on one, or more of its properties (e.g. polarization, frequency) play an enabling role for a wide range of physical phenomena. For example, polarizers can selectively transmit light based on its polarization [1] over a wide range of frequencies; photonic crystals [2] (PhCs) can reflect light of certain frequenci...

Periodic dielectric materials offer a great deal of control over the propagation of light.1 Usually the basic idea is to design periodic dielectric structures that have a band gap for a particular frequency range. In a recent study2 Meade et al. showed that defects in a three-dimensional (3-D) periodic dielectric material (photonic crystal) can admit localized states within a band gap. It is th...