20,645 research outputs found

    Symmetry breaking and manipulation of nonlinear optical modes in an asymmetric double-channel waveguide

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    We study light-beam propagation in a nonlinear coupler with an asymmetric double-channel waveguide and derive various analytical forms of optical modes. The results show that the symmetry-preserving modes in a symmetric double-channel waveguide are deformed due to the asymmetry of the two-channel waveguide, yet such a coupler supports the symmetry-breaking modes. The dispersion relations reveal that the system with self-focusing nonlinear response supports the degenerate modes, while for self-defocusingmedium the degenerate modes do not exist. Furthermore, nonlinear manipulation is investigated by launching optical modes supported in double-channel waveguide into a nonlinear uniform medium.Comment: 10 page

    Achieving new product success via the synchronization of exploration and exploitation across multiple levels and functional areas

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    While ambidexterity has been identified as a critical prerequisite for new product success, synchronizing exploration and exploitation in practice represents a multifaceted enigma. Ambidexterity is not in reality limited to a single organizational level, or a specific functional area. Firms become ambidextrous when corporate-level exploratory and exploitative strategies interact with operational-level exploratory and exploitative capabilities across multiple functional areas. Data from a sample of technology-intensive industrial firms using a multi-informant design shows that operational-level exploratory and exploitative product innovation and marketing capabilities allow firms to implement corporate-level exploratory and exploitative strategies in the context of new product development (NPD). Further, the findings reveal that the integration of exploratory product innovation–exploratory marketing and exploitative product innovation–exploitative marketing is significant for the implementation of exploratory and exploitative strategies over deploying each capability in isolation. Finally, we show that the implementation of exploratory and exploitative strategies drives new product success through creating distinct positional advantages to customers in the form of both differentiation and cost efficiency. These positional advantages help to better explain the effects of exploratory and exploitative capabilities on new product market performance.11 page(s

    Phonon arithmetic in a trapped ion system

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    Single-quantum level operations are important tools to manipulate a quantum state. Annihilation or creation of single particles translates a quantum state to another by adding or subtracting a particle, depending on how many are already in the given state. The operations are probabilistic and the success rate has yet been low in their experimental realization. Here we experimentally demonstrate (near) deterministic addition and subtraction of a bosonic particle, in particular a phonon of ionic motion in a harmonic potential. We realize the operations by coupling phonons to an auxiliary two-level system and applying transitionless adiabatic passage. We show handy repetition of the operations on various initial states and demonstrate by the reconstruction of the density matrices that the operations preserve coherences. We observe the transformation of a classical state to a highly non-classical one and a Gaussian state to a non-Gaussian one by applying a sequence of operations deterministically

    Momentum-Resolved Electronic Structure of the High-TcT_{c} Superconductor Parent Compound BaBiO3_{3}

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    We investigate the band structure of BaBiO3_{3}, an insulating parent compound of doped high-TcT_{c} superconductors, using \emph{in situ} angle-resolved photoemission spectroscopy on thin films. The data compare favorably overall with density functional theory calculations within the local density approximation, demonstrating that electron correlations are weak. The bands exhibit Brillouin zone folding consistent with known BiO6_{6} breathing distortions. Though the distortions are often thought to coincide with Bi3+^{3+}/Bi5+^{5+} charge ordering, core level spectra show that bismuth is monovalent. We further demonstrate that the bands closest to the Fermi level are primarily oxygen derived, while the bismuth 6s6s states mostly contribute to dispersive bands at deeper binding energy. The results support a model of Bi-O charge transfer in which hole pairs are localized on combinations of the O 2p2p orbitals.Comment: minor changes to text and other figures; includes link to online Supplemental Material; accepted to Phys. Rev. Let

    Averaging approximation to singularly perturbed nonlinear stochastic wave equations

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    An averaging method is applied to derive effective approximation to the following singularly perturbed nonlinear stochastic damped wave equation \nu u_{tt}+u_t=\D u+f(u)+\nu^\alpha\dot{W} on an open bounded domain DRnD\subset\R^n\,, 1n31\leq n\leq 3\,. Here ν>0\nu>0 is a small parameter characterising the singular perturbation, and να\nu^\alpha\,, 0α1/20\leq \alpha\leq 1/2\,, parametrises the strength of the noise. Some scaling transformations and the martingale representation theorem yield the following effective approximation for small ν\nu, u_t=\D u+f(u)+\nu^\alpha\dot{W} to an error of \ord{\nu^\alpha}\,.Comment: 16 pages. Submitte

    Raman scattering study of (Kx_xSr1x_{1-x})Fe2_2As2_2 (xx = 0.0, 0.4)

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    Polarized Raman spectra of non-superconducting SrFe2_2As2_2 and superconducting K0.4_{0.4}Sr0.6_{0.6}Fe2_2As2_2 (Tc=37T_c = 37 K) are reported. All four phonon modes (A1g_{1g} + B1g_{1g} + 2Eg_g) allowed by symmetry, are found and identified. Shell model gives reasonable description of the spectra. No detectable anomalies are observed near the tetragonal-to-orthorhombic transition in SrFe2_2As2_2 or the superconducting transition in K0.4_{0.4}Sr0.6_{0.6}Fe2_2As2_2.Comment: 4 pages, 4 figures, 2 table
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