2,789 research outputs found

    Lifshitz Scaling Effects on Holographic Superconductors

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    Via numerical and analytical methods, the effects of the Lifshitz dynamical exponent zz on holographic superconductors are studied in some detail, including ss wave and pp wave models. Working in the probe limit, we find that the behaviors of holographic models indeed depend on concrete value of zz. We obtain the condensation and conductivity in both Lifshitz black hole and soliton backgrounds with general zz. For both ss wave and pp wave models in the black hole backgrounds, as zz increases, the phase transition becomes more difficult and the growth of conductivity is suppressed. For the Lifshitz soliton backgrounds, when zz increases (z=1, 2, 3z=1,~2,~3), the critical chemical potential decreases in the ss wave cases but increases in the pp wave cases. For pp wave models in both Lifshitz black hole and soliton backgrounds, the anisotropy between the AC conductivity in different spatial directions is suppressed when zz increases. The analytical results uphold the numerical results.Comment: Typos corrected; Footnote added; References added; To be published in Nuclear Physics

    Negative refraction with little loss manipulated by the voltage and pulsed laser in double quantum dots

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    The paper demonstrates that negative refractive index can be achieved via tuning the tunneling rate between a double quantum dots(QDs) system by applying a bias voltage, and a pulsed laser. As the bias voltage being changed, the refraction index can be tunable to negative with the simultaneous negative permittivity and permeability. While the varying pulsed laser is applied to the double QDs system, moreover, the negative refractive index with little loss can be obtained. The flexible manipulation on a solid state system to realize negative refraction may give a new way for experimental research in the future.Comment: 10 pages, 6 figure

    Tetra­aqua­bis(3-carboxyl­atopyridine N-oxide-κO 3)cadmium(II)

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    In the title complex, [Cd(C6H4NO3)2(H2O)4], the CdII atom is situated on a crystallographic centre of inversion. The CdII atom shows a slightly distorted octa­hedral geometry and is coordinated by four O atoms from water mol­ecules and two O atoms from deprotonated carboxyl groups of nicotinic acid N-oxide ligands. The mononuclear complex mol­ecules are linked by O—H⋯O hydrogen bonds, forming a three-dimensional network structure

    Tetra-μ-acetato-bis­[(pyridine N-oxide)copper(II)](Cu—Cu)

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    The mol­ecule of the title binuclear copper(II) complex, [Cu2(CH3COO)4(C5H5NO)2], occupies a special position on a crystallographic inversion centre; the coordination environment of the CuII atom is slightly distorted square-pyramidal and is made up of four O atoms belonging to four acetate groups in the basal plane with the O atom of pyridine N-oxide ligand in the apical position. The Cu—Cu distance is 2.6376 (6) Å

    Two types of generalized integrable decompositions and new solitary-wave solutions for the modified Kadomtsev-Petviashvili equation with symbolic computation

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    The modified Kadomtsev-Petviashvili (mKP) equation is shown in this paper to be decomposable into the first two soliton equations of the 2N-coupled Chen-Lee-Liu and Kaup-Newell hierarchies by respectively nonlinearizing two sets of symmetry Lax pairs. In these two cases, the decomposed (1+1)-dimensional nonlinear systems both have a couple of different Lax representations, which means that there are two linear systems associated with the mKP equation under the same constraint between the potential and eigenfunctions. For each Lax representation of the decomposed (1+1)-dimensional nonlinear systems, the corresponding Darboux transformation is further constructed such that a series of explicit solutions of the mKP equation can be recursively generated with the assistance of symbolic computation. In illustration, four new families of solitary-wave solutions are presented and the relevant stability is analyzed.Comment: 23 page

    Penta­aqua­(1H-benzimidazole-5,6-di­carboxyl­ato-κN 3)copper(II) penta­hydrate

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    The title compound, [Cu(C9H4N2O4)(H2O)5]·5H2O, contains one crystallographically independent CuII atom and one 1H-benzimidazole-5,6-dicarboxyl­ate (bdc) ligand, along with five coordinated and five uncoordinated water mol­ecules. The CuII atom is six-coordinated by one N atom from the bdc ligand and five O atoms from water mol­ecules, giving an octa­hedral coordination geometry. Hydrogen bonds link the mononuclear complex and uncoordinated water mol­ecules into a three-dimensional network

    catena-Poly[silver(I)-μ-pyrazolato-κ2 N:N′]

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    The title compound, [Ag(C3H3N2)]n, has an infinite helical chain structure in which each pyrazolate group bridges two AgI atoms related by a 21 axis with an intra­chain Ag⋯Ag separation of 3.3718 (7) Å. Each AgI center is linearly coordinated by two N atoms [N—Ag—N angle = 169.98 (14)°]. The chains are held together by inter­chain Ag⋯Ag inter­actions [3.2547 (6) Å], forming a two-dimensional layer. The X-ray single-crystal diffraction result is consonant with that of the ab initio X-ray powder diffraction reported by Masciocchi, Moret, Cairati, Sironi, Ardizzoia & La Monica [J. Am. Chem. Soc. (1994). 116, 7668–7676], with only minor deviations of structural parameters

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