Self-organized voids revisited:Experimental verification of the formation mechanism

We conduct several experiments to further clarify the formation mechanism of a self-organized void array induced by a single laser beam, including energy-related experiments, refractive-index-contrast-related experiments, depth-related ex- periments, and effective-numerical-aperture experiment. These experiments indicate that the interface spherical aberration is indeed responsible for the formation of void arrays.     

Emergent universe scenario via Quintom matter

The emergent universe scenario provides a possible alternative to bouncing cosmology to avoid the Big Bang singularity problem. In this Letter we study the realization of the emergent universe scenario by making use of Quintom matter with an equation of state across the cosmological constant boundary. We will show explicitly the analytic and numerical solutions of emergent universe in two Quintom models, which are a phenomenological fluid and a nonconventional spinor field, respectively.     

On the crossing of thin shells

The crossing of two dust shells is considered as a simplified model of a collapsing thick layer of dust. We use the Israel's formalism to describe the development of two shells of dust which interact only gravitationally. The formalism is developed in both Schwarzschild and Kruskal coordinates.     

Mesoscopic samples: the superconducting condensate via the Gross-Pitaevskii scenario

Mesoscopic superconductors are routinely investigated with the Ginzburg-Landau equations, whereby the confinement is taken into account by imposing that the normal component of the superconducting current vanishes through the sample boundary. We argue that this approach gives misleading results when applied to micron- and submicron-sized devices, and we introduce modified Ginzburg-Landau equations that take the confinement potential into account on the level of the free energy functional. For devices much larger than the Ginzburg-Landau coherence length, both approaches agree, but deviations appear for samples of the scale of the coherence length. In the absence of a magnetic field, the modified Ginzburg-Landau equation for the order parameter reduces to the Gross-Pitaevskii equation.     

On self-organized shell formation by bovine carbonic anhydrase II, and soluble protein extracted from regenerated shell

The soluble protein of hemocytes from diseased shell (HDS) of oyster, Crassostrea gigas, was shown to play a key role in the rapid growth of calcium carbonate crystals. In this study, we compared HDS extracted from regenerated (or diseased) shell with bovine carbonic anhydrase II in terms of their ability to promote the growth of calcium carbonate crystals. On the basis of scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) analysis, a high growth rate of calcium carbonate crystals was identified under artificial seawater and atmospheric temperature. The function and role of HDS extracted from regenerated shell are discussed at the molecular point as compared to aragonite-specific soluble proteins. Our findings suggest that hemocytes function as a soluble protein, with repeated GX (G: Gly, X: Asp, Asn or Glu) or negative charged amino acid domains binding calcium and specific surface features for catalyzing rapid shell regeneration.     

New evidence of positronium formation in neutron-irradiated molybdenum crystal containing voids

A new evidence for the presence of positronium atom in neutron-irradiated molybdenum crystal containing voids has been observed. A negative positronium work function for molybdenum has been indicated.     

Muonium in condensed neon: Spur formation scenario

The details of muonium formation via recombination of the thermalized muon and electron are discussed on the basis of μSR experiments in condensed neon, which are interpreted in the framework of the isolated μ^+- e^- pair model. The comparison of the results in different substances is made. In this context, the limits of the model, as well as possible extra factors, which can affect muonium formation, are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Topological scenario for stripe formation in manganese oxides

The spin-charge-orbital complex structures of manganites are studied using topological concepts. The key quantity is the "winding number" w associated with the Berry-phase connection of an e(g) electron parallel transported through Jahn-Teller centers, along zigzag one-dimensional paths in an antiferromagnetic environment of t(2g) spins. From these concepts, it is shown that the "bi-stripe" and "Wigner-crystal" states observed experimentally have different w's. Predictions for the spin structure of the charge-ordered states for heavily doped manganites are discussed.     

Acoustic topological adiabatic passage via a level crossing

Stimulated adiabatic passage has been extensively studied to achieve robust and selective population transfer in quantum systems. Recently, the quantum-classic analogy has been rapidly developing and can be considered responsible for the implementation of the adiabatic transfer of sound energy in cavity chain systems. In this article, we investigate the adiabatic transfer of sound energy between two topological end states in the Su-Schrieffer-Heeger(SSH) cavity chain, which can be considered to be the acoustic analog of the quantum chirped-pulse excitation. The topological adiabatic passage in SSH cavity chain has two categories. When the single-cavity resonance frequencies on the sublattices A and B in the SSH cavity chain do not switch their spectrum positions, the topologically protected adiabatic evolution results in the returning passage of the sound excited in one end cavity. When a level crossing with single-cavity resonance frequencies on the sublattices A and B exhibits switch in the frequency spectrum, acoustic energy is observed to be topologically pumped between the two end cavities of the SSH chain.     

On the universality of crossing probabilities in two-dimensional percolation

Six percolation models in two dimensions are studied: percolation by sites and by bonds on square, hexagonal, and triangular lattices. Rectangles of widtha and heightb are superimposed on the lattices and four functions, representing the probabilities of certain crossings from one interval to another on the sides, are measured numerically as functions of the ratioa/b. In the limits set by the sample size and by the conventions and on the range of the ratioa/b measured, the four functions coincide for the six models. We conclude that the values of the four functions can be used as coordinates of the renormalization-group fixed point.     

Scalar \sigma meson via chiral and crossing dynamics

We show that the non-strange scalar s\sigma meson, as now reported in the 1996 PDG tables, is a natural consequence of crossing symmetry as well as chiral dynamics for both strong interaction low energy pp\pi\pi scattering and also K ? 2pK \to 2\pi weak decays.     

On the percolation BCFT and the crossing probability of Watts

The logarithmic conformal field theory describing critical percolation is further explored using Watts' determination of the probability that there exists a cluster connecting both horizontal and vertical edges. The boundary condition changing operator which governs Watts' computation is identified with a primary field which does not fit naturally within the extended Kac table. Instead a “shifted” extended Kac table is shown to be relevant. Augmenting the previously known logarithmic theory based on Cardy's crossing probability by this field, a larger theory is obtained, in which new classes of indecomposable rank-2 modules are present. No rank-3 Jordan cells are yet observed. A highly non-trivial check of the identification of Watts' field is that no Gurarie–Ludwig-type inconsistencies are observed in this augmentation. The article concludes with an extended discussion of various topics related to extending these results including projectivity, boundary sectors and inconsistency loopholes.     

Ground state of the hydrogen atom via Dirac equation in a minimal-length scenario

The European Physical Journal C - I consider the generic model independent predictions of the theory of quantum cosmological perturbations. To describe the stage of cosmic inflation, where these...     

On the construction of analytic and crossing symmetric partial waves

The problem of construction of analytic and crossing symmetric partial waves leads to a generalized Riesz problem. In some cases nontrivial solutions can be constructed from the solutions of a homogeneous Fredholm integral equation. It is suggested that the unitary partial waves satisfy a similar equation.Work performed under contract with the Rumanian Nuclear Energy Committee.     

On the crossing feature of phonon dispersion curves in lithium

Krebs' model for the lattice dynamics of cubic metals has been modified to include the effects of correlation and exchange in the electron gas. This formulation is applied to compute the phonon frequencies of lithium in the major symmetry directions. It has been found that such modification plays an important role in reproducing the observed crossing of longitudinal and transverse modes in the [100] direction. Overall agreement between the theoretical and experimental curves for lithium is found to be excellent.     

On the formation process of silicon carbide nanophases via hydrogenated thermally induced templated synthesis

A thermally induced templated synthesis for SiC nanotubes and nanofibers is presented using ammonia or N₂ with vaporized Si is presented. The bundles of SWCNT act as both the carbon source and as a nanoframe from which SiC structures form. Depending on the duration of the thermally induced templated reaction, various SiC nanostructures are obtained for a fixed temperature, carrier gas, and gas pressure. These structures include SiC nanorods coated in C, SiC nanorods, SiC nanotubes, and SiC nanocrystals. PACS 07.80.+x; 61.82.Rx; 68.37.Lp; 73.63.Fg; 81.07.-b;81.07.Bc; 81.07.De; 29.30.Dn     

On the geometric foundations of nuclear shell structure

Cartan's geometric theory of partial differential equations is applied to a system of Schrödinger equations. It is shown that the choice of a Riemann manifold which is a torus is equivalent to using a many-body neutron and proton potential commonly used in nuclear theory. The theory is applied to spinless, ground-state systems using the Dirichlet principle to minimise the energy, to obtain the neutron-proton ratios, Coulomb and binding energies of nuclei. A shell structure naturally manifests itself from the choice of the manifold.