Abstract:
the optical properties of exciton polaritons in one-dimensional photonic crystals are theoretically investigated. the periodic photonic structure is formed by two alternating layers, namely a local dielectric layer and a thin semiconductor one which is characterized by a nonlocal excitonic dielectric function. we calculate reflectivity spectra for one-dimensional mgo-cucl photonic crystals, which exhibit a rich resonance structure because of the optical manifestation of size-quantized excitons. we study the changes in the resonance structure as the thickness of the thin semiconductor layer is varied. it is found that odd quantized-exciton modes are well manifest in the optical spectra in comparison with even states. we have also investigated the effect of both homogeneous bulk damping and interface-induced broadening upon the reflectivity resonances. the broadening due to interface disorder is calculated with the self-consistent green's function method.

Abstract:
The optical properties of exciton polaritons in one-dimensional photonic crystals are theoretically investigated. The periodic photonic structure is formed by two alternating layers, namely a local dielectric layer and a thin semiconductor one which is characterized by a nonlocal excitonic dielectric function. We calculate reflectivity spectra for one-dimensional MgO-CuCl photonic crystals, which exhibit a rich resonance structure because of the optical manifestation of size-quantized excitons. We study the changes in the resonance structure as the thickness of the thin semiconductor layer is varied. It is found that odd quantized-exciton modes are well manifest in the optical spectra in comparison with even states. We have also investigated the effect of both homogeneous bulk damping and interface-induced broadening upon the reflectivity resonances. The broadening due to interface disorder is calculated with the self-consistent Green's function method.

Abstract:
The combined effect of finite potential barriers and dielectric mismatch between dot and matrix on excitonic properties of semiconductor quantum dots has been studied. To avoid the unphysical divergence in the self-polarization energy which arises for the simplest and profusely adopted step-like model of the dielectric interface, we proposed a realistic (finite size) smooth profile for the dielectric interface. We have found that the excitonic binding energy can be either higher than the corresponding one to complete confinement by infinite barriers or essentially zero for a wide range of dot sizes depending on the thickness of the dielectric interface.

Abstract:
We study the dielectric function of the homogeneous hole gas in p-doped zinc-blende III-V bulk semiconductors within random phase approximation with the valence band being modeled by Luttinger's Hamiltonian in the spherical approximation. In the static limit we find a beating of Friedel oscillations between the two Fermi momenta for heavy and light holes, while at large frequencies dramatic corrections to the plasmon dispersion occur.

Abstract:
We study the dielectric function of the homogeneous semiconductor hole liquid of p-doped bulk III-V zinc-blende semiconductors within random phase approximation. The single-particle physics of the hole system is modeled by Luttinger's four-band Hamiltonian in its spherical approximation. Regarding the Coulomb-interacting hole liquid, the full dependence of the zero-temperature dielectric function on wave vector and frequency is explored. The imaginary part of the dielectric function is analytically obtained in terms of complicated but fully elementary expressions, while in the result for the real part nonelementary one-dimensional integrations remain to be performed. The correctness of these two independent calculations is checked via Kramers-Kronig relations. The mass difference between heavy and light holes, along with variations in the background dielectric constant, leads to dramatic alternations in the plasmon excitation pattern, and generically, two plasmon branches can be identified. These findings are the result of the evaluation of the full dielectric function and are not accessible via a high-frequency expansion. In the static limit a beating of Friedel oscillations between the Fermi wave numbers of heavy and light holes occurs.

Abstract:
We theoretically study the effect of the dielectric environment on the exciton ground state of CdSe and CdTe/CdSe/CdTe nanorods. We show that insulating environments enhance the exciton recombination rate and blueshift the emission peak by tens of meV. These effects are particularly pronounced for type-II nanorods. In these structures, the dielectric confinement may even modify the spatial distribution of electron and hole charges. A critical electric field is required to separate electrons from holes, whose value increases with the insulating strength of the surroundings.

Abstract:
In this paper, an exciton-photon model is created in an optic microcavity, and then in Bose condensation (BC), the variations of chemical potential range and number density of particles with temperature and position are studied in cases: constant width and varying width. Taking a semiconductor optic microcavity GaAs as example, the influence of temperature on BC is analyzed. The result shows that the range of chemical potential is related to dielectric function and microcavity width, while the number densities of photons and excitons and the sum of both particle numbers are related not only to them but also to temperature. The theoretical temperature of BC of GaAs is close to the experimental value. The densities of photons and excitons are almost equal, and their distributions are restricted to r=0 when BC occurs. With the reduction of temperature the number densities of both particles increase and their distributions expand, and the number of photons is more than that of excitons no matter how the width of optic microcavity changes.

Abstract:
The inverse dielectric function of semiconductor superlattices is derived with inclusion of tunneling effects between adjacent quantum wells. The result is, then, used to evaluate the fast electron energy-loss-spotrum with the conclusion that tunneling effect tend to enhance the energy loss in superlattices.

Abstract:
In this paper, we introduced the dressed exciton model of the semiconductor micro-cavity device. In the semiconductor micro cavity of vertical-cavity surface-emission device, the excitons first coupled with the cavity through an intra-electromagnetic field and formed the dressed excitons. Then these dressed excitons decayed into the vacuum cavity optical mode, as a multi-particle process. Through the quantum electrodynamics method, the dipole emission density and system energy decayed equation were obtained. And it was predicted that the excitons decay into a very narrow mode when the exciton-cavity coupling becomes strong enough.

Abstract:
A variational calculation of the ground-state energy of neutral excitons and of positively and negatively charged excitons (trions) confined in a single-quantum well is presented. We study the dependence of the correlation energy and of the binding energy on the well width and on the hole mass. The conditional probability distribution for positively and negatively charged excitons is obtained, providing information on the correlation and the charge distribution in the system. A comparison is made with available experimental data on trion binding energies in GaAs-, ZnSe-, and CdTe-based quantum well structures, which indicates that trions become localized with decreasing quantum well width.