Vladimir S. Boyko

Graphene-based photonic crystal

A novel type of photonic crystal formed by embedding a periodic array of constituent stacks of alternating graphene and dielectric discs into a background dielectric medium is proposed. The photonic band structure and transmittance of such photonic crystal are calculated. The graphene-based photonic crystals can be used effectively as the frequency filters and waveguides for the far infrared region of electromagnetic spectrum. Due to substantial suppression of absorption of low-frequency radiation in doped graphene the damping and skin effect in the photonic crystal are also suppressed. The advantages of the graphene-based photonic crystal are discussed.

The estimation of the thickness of the nonsuperconducting layer at the interfaces in YBa2Cu3O7−δ

Abstract The results of a computer simulation of the atomic structure of interfaces in YBa2Cu3O7−δ (twin boundary and large-angle symmetrical tilt grain boundary) are presented. These results allow us to determine the lattice displacements and distortions in the vicinity of analyzed interfaces. Basing on the strain level ≈ 0.01 as a phenomenological criterion for the suppression of superconductivity, estimates of the thickness of the nonsuperconducting regions enveloping interfaces are made.

Extended defects in natural diamonds: An Atomic Force Microscopy investigation

Abstract Surfaces of natural diamonds etched in high-pressure experiments in H2O, CO2 and H2O–NaCl fluids were investigated using Atomic Force Microscopy. Partial dissolution of the crystals produced several types of surface features including the well-known trigons and hillocks and revealed several new types of defects. The most remarkable ones are assigned to twins of several types. The observation of abundant microtwins, ordering of hillocks, and presence of defects presumably related to knots of branched dislocations suggests importance of post-growth deformation events on formation of diamond microstructure. This work confirms previous reports of ordering of extended defects in some deformed diamonds. In addition, the current study shows that natural diamonds deform not only by slip, but also by mechanical twinning. The dominant mechanism should depend on pressure–temperature–stress conditions during diamond transport from the formation domain to the Earth surface.

Anomalous far-infrared monochromatic transmission through a film of type-II superconductor in magnetic field

Anomalous far infrared monochromatic transmission through a lattice of Abrikosov vortices in a type-II superconducting film is found and reported. The transmitted frequency corresponds to the photonic mode localized by the defects of the Abrokosov lattice. These defects are formed by extra vortices placed out of the nodes of the ideal Abrokosov lattice. The extra vortices can be pinned by crystal lattice defects of a superconductor. The corresponding frequency is studied as a function of magnetic field and temperature in the framework of the Dirac-type two-band model. While our approach is valid for all type-II superconductors, the specific calculations have been performed for the YBa

Monochromatic infrared wave propagation in 2D superconductor-dielectric photonic crystal

_{2}

Instability in the current-biased 0-{pi} Josephson junction

Cu

Twinning propensity in nanocrystalline face-centered cubic, body-centered cubic, and hexagonal close-packed metals

_{3}

Twinning in nanocrystalline materials

O

On transmittance and localization of the electromagnetic wave in two-dimensional graphene-based photonic crystals

_{7-\delta}

Transport properties of large-angle grain boundaries containing point defects inYBa2Cu3O7−δ

(YBCO). The control of the transmitted frequency by varying magnetic field and/or temperature is analyzed. It is suggested that found anomalously transmitted localized mode can be utilized in the far infrared monochromatic filters.