arXiv subjects

A. N. Poddubny

Publications and source records attributed to A. N. Poddubny.

40 records · Page 3Linked to original sources

arXiv2007

Low-frequency spectroscopy of superconducting photonic crystals

Transmission, reflection and absorption of electromagnetic radiation and photon dispersion law for 2D photonic crystals with superconducting elements are studied. The calculation of optical properties of photonic crystals is studied by layer-by-layer Korringa-Kohn-Rostoker techniques. The results of numerical calculations performed for an array of superconducting cylinders have been understood in terms of a simple analytical model. The controlling of optical properties of superconducting photonic crystal by temperature and magnetic field is discussed. The variation of superconducting component density with temperature leads, particularly, to significant reduction of the transmission peaks and even to a nonmonotonous behavior of some absorbance peaks.

cond-mat.mes-hall↗

arXiv2007

Coherent defect-assisted multiphonon intraband carrier relaxation in semiconductor quantum dots

new defect-assisted mechanism of multiphonon intraband carrier relaxation in semiconductor quantum dots, where the carrier is found in a coherent superposition of the initial, final, and defect states, is proposed. It is shown that this mechanism is capable of explaining the observed trends in temperature dependences of the intraband relaxation rates for PbSe and CdSe colloidal nanocrystal quantum dots.

cond-mat.mes-hall↗

arXiv2006

Special frequencies in reflection spectra of Bragg multiple quantum well structures

We have studied theoretically optical reflection spectra from the Bragg multiple quantum well structures. We give an analytical explanation of the presence of two special frequencies in the spectra at which the reflection coefficient weakly depends on the quantum well number. The influence of the exciton nonradiative damping on the reflection spectra has been analyzed. It has been shown that allowance for the dielectric contrast gives rise to the third special frequency at which the contributions to the reflectivity related to the dielectric contrast and the exciton resonance mutually compensate one another.

cond-mat.mes-hall↗

arXiv2005

Resonant three-dimensional photonic crystals

We have developed a theory of exciton-polariton band structure of resonant three-dimensional photonic crystals for arbitrary dielectric contrast and effective mass of the exciton that is excited in one of the compositional materials. The calculation has been carried out for a periodic array of spheres embedded in a dielectric matrix. It has been shown that the position of the lower branches of the polariton dispersion curve monotonously depends on the exciton effective mass and is determined by the coupling of light with the first few states of the mechanical exciton quantum confined inside each sphere. Particularly, we have studied the role of excitonic effects on the photonic-crystal band gap along the [001] direction of the Brillouin zone and presented an analytic description of the polariton dispersion in terms of the two-wave approximation.

cond-mat.mes-hall↗