379 research outputs found

    The process of postmerger integration : a review and agenda for future research

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    Mergers and acquisitions (M&As) continue to be prevalent despite frequently yielding disappointing outcomes. Postmerger integration plays a critical role in M&A success, yet many questions about M&A implementation remain unanswered. In this article, we review research on postmerger integration, which we organize around strategic integration, sociocultural integration, and experience and learning. We then lay out a research agenda that centers on expanding our understanding of processual dynamics in postmerger integration. We focus on opportunities related to temporality, decision-making, practices and tools, and emotionality

    Quasiparticle Density of States of Clean and Dirty s-Wave Superconductors in the Vortex State

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    The quasiparticle density of states (DOS) in the vortex state has been probed by specific heat measurements under magnetic fields (H) for clean and dirty s-wave superconductors, Y(Ni1-xPtx)2B2C and Nb1-xTaxSe2. We find that the quasiparticle DOS per vortex is appreciably H-dependent in the clean-limit superconductors, while it is H-independent in the dirty superconductors as expected from a conventional rigid normal electron core picture. We discuss possible origins for our observations in terms of the shrinking of the vortex core radius with increasing H.Comment: 5 pages, 4 figures, to appear in J. Phys. Soc. Jpn. Vol. 68 No.

    Evidence for a Second Order Phase Transition in Glasses at Very Low Temperatures -- A Macroscopic Quantum State of Tunneling Systems

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    Dielectric measurements at very low temperature indicate that in a glass with the eutectic composition BaO-Al2_2O3_3-SiO2_2 a phase transition occurs at 5.84 mK. Below that temperature small magnetic fields of the order of 10 μ\muT cause noticeable changes of the dielectric constant although the glass is insensitive to fields up to 20 T above 10 mK. The experimental findings may be interpreted as the signature of the formation of a new phase in which many tunneling systems perform a coherent motion resulting in a macroscopic wave function.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

    Local density of states in the vortex lattice in a type II superconductor

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    Local density of states (LDOS) in the triangular vortex lattice is investigated based on the quasi-classical Eilenberger theory. We consider the case of an isotropic s-wave superconductor with the material parameter appropriate to NbSe_2. At a weak magnetic field, the spatial variation of the LDOS shows cylindrical structure around a vortex core. On the other hand, at a high field where the core regions substantially overlap each other, the LDOS is sixfold star-shaped structure due to the vortex lattice effect. The orientation of the star coincides with the experimental data of the scanning tunneling microscopy. That is, the ray of the star extends toward the nearest-neighbor (next nearest-neighbor) vortex direction at higher (lower) energy.Comment: 10 pages, RevTex, 32 figure

    Absence of Persistent Magnetic Oscillations in Type-II Superconductors

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    We report on a numerical study intended to examine the possibility that magnetic oscillations persist in type II superconductors beyond the point where the pairing self-energy exceeds the normal state Landau level separation. Our work is based on the self-consistent numerical solution for model superconductors of the Bogoliubov-deGennes equations for the vortex lattice state. In the regime where the pairing self-energy is smaller than the cyclotron energy, magnetic oscillations resulting from Landau level quantization are suppressed by the broadening of quasiparticle Landau levels due to the non-uniform order parameter of the vortex lattice state, and by splittings of the quasiparticle bands. Plausible arguments that the latter effect can lead to a sign change of the fundamental harmonic of the magnetic oscillations when the pairing self-energy is comparable to the cyclotron energy are shown to be flawed. Our calculations indicate that magnetic oscillations are strongly suppressed once the pairing self-energy exceeds the Landau level separation.Comment: 7 pages, revtex, 7 postscript figure

    Electron Dephasing in Mesoscopic Metal Wires

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    The low-temperature behavior of the electron phase coherence time, τϕ\tau_{\phi}, in mesoscopic metal wires has been a subject of controversy recently. Whereas theory predicts that τϕ(T)\tau_{\phi}(T) in narrow wires should increase as T2/3T^{-2/3} as the temperature TT is lowered, many samples exhibit a saturation of τϕ\tau_{\phi} below about 1 K. We review here the experiments we have performed recently to address this issue. In particular we emphasize that in sufficiently pure Ag and Au samples we observe no saturation of τϕ\tau_{\phi} down to our base temperature of 40 mK. In addition, the measured magnitude of τϕ\tau_{\phi} is in excellent quantitative agreement with the prediction of the perturbative theory of Altshuler, Aronov and Khmelnitskii. We discuss possible explanations why saturation of τϕ\tau_{\phi} is observed in many other samples measured in our laboratory and elsewhere, and answer the criticisms raised recently by Mohanty and Webb regarding our work.Comment: 14 pages, 3 figures; to appear in proceedings of conference "Fundamental Problems of Mesoscopic Physics", Granada, Spain, 6-11 September, 200
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