abstract the spontaneous emission spectrum from a driven three-level atom placed inside a double-band photonic crystal has been investigated. we use the model which assumes the upper levels of the atomic transition are coupled via a classical driving field. the transition from one of the upper levels to lower level couples to the modes of the modified reservoir, and the transition from the othe...

in the present paper, resonant frequencies and modes of a three-atom photonic molecule and a photonic crystal placed within a cavity are numerically calculated. first, governing formulation in transverse electric field mode (te) is obtained using maxwell equations. then, an algorithm based on a finite difference scheme and matrix algebra is presented. the algorithm is then implemented in a comp...

The theory of the macroscopic field appearing in the Kohn-Sham exchange-correlation potential for dielectric materials, as introduced by Gonze, Ghosez, and Godby [Phys. Rev. Lett. 78, 294 (1997)], is reexamined. It is shown that this Kohn-Sham field cannot be determined from a knowledge of the local state of the material (local crystal potential, electric field, and polarization) alone. Instead...

The orientation fluctuations of the director of a liquid crystal are measured, by a sensitive polarization interferometer, close to the Fréedericksz transition, which is a second order transition driven by an electric field. Using mean field theory, we define the work injected into the system by a change of the electric field and we calibrate it using Fluctuation-Dissipation Theorem. We show th...

We present a theoretical investigation of the temperature and electric field dependence of nematic liquid crystal wetting layers close to an aligning substrate within a confined system. Using a mesoscopic Q tensor theory coupled to Maxwell’s equations for the electric field, we consider the existence and stability of homogeneous nematic wetting layers close to the substrate. Numerical results a...

Crystal field parameters for two nonequivalent positions Ca (I) and (II) hydroxyapatite (HAp) crystals from the density functional theory (DFT) are calculated. Calculations compared with experimental electron paramagnetic resonance (EPR) spectra (registered at microwave frequencies) synthesized Mn-HAp powders Ca9.995Mn0.005(PO4)6(OH)2. It is found that in investigated species, manganese redistr...

2014 A beautiful striped texture is often observed as the initial response of a uniformly aligned nematic liquid crystal to a suddenly applied reorienting field The structure of the instability depends on the elastic and viscous anisotropy of the liquid crystal, the field strength, and in an important way on the boundary conditions imposed by the sample cell. We have studied the geometry in whi...

Structural aspects of crystal nucleation in undercooled liquids are explored using a nonlinear hydrodynamic theory of crystallization proposed recently [G. I. Tóth et al., J. Phys.: Condens. Matter 26, 055001 (2014)JCOMEL0953-898410.1088/0953-8984/26/5/055001], which is based on combining fluctuating hydrodynamics with the phase-field crystal theory. We show that in this hydrodynamic approach n...