14,110 research outputs found

    Earnouts: A Study of Financial Contracting in Acquisition Agreements

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    We empirically examine earnout contracts, which provide for contingent payments in acquisition agreements. Our analysis reveals considerable heterogeneity in the terms of earnout contracts, i.e. the potential size of the earnout, the performance measure on which the contingent payment is based, the period over which performance is measured, the frequency with which performance is measured, and the form of payment for the earnout. Consistent with the costly contracting hypothesis, we find that the terms of earnout contracts are associated with measures of target valuation uncertainty, target growth opportunities, and the degree of post-acquisition integration between target and acquirer. We conclude that earnouts are structured to minimize the costs of adverse selection and moral hazard in acquisition negotiations.

    Spin relaxation and decoherence of holes in quantum dots

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    We investigate heavy-hole spin relaxation and decoherence in quantum dots in perpendicular magnetic fields. We show that at low temperatures the spin decoherence time is two times longer than the spin relaxation time. We find that the spin relaxation time for heavy holes can be comparable to or even longer than that for electrons in strongly two-dimensional quantum dots. We discuss the difference in the magnetic-field dependence of the spin relaxation rate due to Rashba or Dresselhaus spin-orbit coupling for systems with positive (i.e., GaAs quantum dots) or negative (i.e., InAs quantum dots) gg-factor.Comment: 5 pages, 1 figur

    Mechanism of metallization and superconductivity suppression in YBa2(_2(Cu0.97_{0.97}Zn0.03)3_{0.03})_3O6.92_{6.92} revealed by 67^{67}Zn NQR

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    We measure the nuclear quadrupole resonance (NQR) signal on the Zn site in nearly optimally doped YBa2_2Cu3_3O6.92_{6.92}, when Cu is substituted by 3\% of isotopically pure 67^{67}Zn. We observe that Zn creates large insulating islands, confirming two earlier conjectures: that doping provokes an orbital transition in the CuO2_2 plane, which is locally reversed by Zn substitution, and that the islands are antiferromagnetic. Also, we find that the Zn impurity locally induces a breaking of the D4_4 symmetry. Cluster and DFT calculations show that the D4_4 symmetry breaking is due to the same partial lifting of degeneracy of the nearest-neighbor oxygen sites as in the LTT transition in La2x_{2-x}Bax_xCuO4_4, similarly well-known to strongly suppress superconductivity. These results show that in-plane oxygen 2p52p^5 orbital configurations are principally involved in the metallicity and superconductivity of all high-Tc_c cuprates, and provide a qualitative symmetry-based constraint on the SC mechanism.Comment: extended version, to appear in New Journal of Physic

    The Lagrangian and Hamiltonian Aspects of the Electrodynamic Vacuum-Field Theory Models

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    We review the modern classical electrodynamics problems and present the related main fundamental principles characterizing the electrodynamical vacuum-field structure. We analyze the models of the vacuum field medium and charged point particle dynamics using the developed field theory concepts. There is also described a new approach to the classical Maxwell theory based on the derived and newly interpreted basic equations making use of the vacuum field theory approach. In particular, there are obtained the main classical special relativity theory relations and their new explanations. The well known Feynman approach to Maxwell electromagnetic equations and the Lorentz type force derivation is also discussed in detail. A related charged point particle dynamics and a hadronic string model analysis is also presented. We also revisited and reanalyzed the classical Lorentz force expression in arbitrary non-inertial reference frames and present some new interpretations of the relations between special relativity theory and its quantum mechanical aspects. Some results related with the charge particle radiation problem and the magnetic potential topological aspects are discussed. The electromagnetic Dirac-Fock-Podolsky problem of the Maxwell and Yang-Mills type dynamical systems is analyzed within the classical Dirac-Marsden-Weinstein symplectic reduction theory. The problem of constructing Fock type representations and retrieving their creation-annihilation operator structure is analyzed. An application of the suitable current algebra representation to describing the non-relativistic Aharonov-Bohm paradox is presented. The current algebra coherent functional representations are constructed and their importance subject to the linearization problem of nonlinear dynamical systems in Hilbert spaces is demonstrated.Comment: 70 p, revie

    Shot Noise Probing of Magnetic Ordering in Zigzag Graphene Nanoribbons

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    The nonequilibrium time-dependent fluctuations of charge current have recently emerged as a sensitive experimental tool to probe ballistic transport through evanescent wave functions introduced into clean wide and short graphene strips by the attached metallic electrodes. We demonstrate that such "pseudo-diffusive" shot noise can be substantially modified in zigzag graphene nanoribbon (ZGNR) due to the topology of its edges responsible for localized states that facilitate ferromagnetic ordering along the edge when Coulomb interaction is taken into account. Thus, the shot noise enhancement of unpolarized, and even more sensitively of spin-polarized, charge currents injected into ZGNR will act as an all-electrical and edge-sensitive probe of such low-dimensional magnetism.Comment: 5 pages, 3 color figures; references update
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