Alcatel-Lucent

About: Alcatel-Lucent is a based out in Stuttgart, Germany. It is known for research contribution in the topics: Signal & Network packet. The organization has 37003 authors who have published 53332 publications receiving 1430547 citations. The organization is also known as: Alcatel-Lucent S.A. & Alcatel.

Absence of ferromagnetism in Co and Mn substituted polycrystalline ZnO

Abstract: We discuss the properties of semiconducting bulk ZnO when substituted with the magnetic transition metal ions Mn and Co, with substituent fraction ranging from $x=0.02$ to $x=0.15$. The magnetic properties were measured as a function of magnetic field and temperature and we find no evidence for magnetic ordering in these systems down to $T=2\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The magnetization can be fit by the sum of a Curie-Weiss term with a Weiss temperature of $\ensuremath{\Theta}⪢100\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ and a Curie term. We attribute this behavior to contributions from both $t\mathrm{M}$ ions with $t\mathrm{M}$ nearest neighbors and from isolated spins. This particular functional form for the susceptibility is used to explain why no ordering is observed in $t\mathrm{M}$ substituted ZnO samples despite the large values of the Weiss temperature. We also discuss in detail the methods we used to minimize any impurity contributions to the magnetic signal.

A cost-based model and effective heuristic for repairing constraints by value modification

Abstract: Data integrated from multiple sources may contain inconsistencies that violate integrity constraints. The constraint repair problem attempts to find "low cost" changes that, when applied, will cause the constraints to be satisfied. While in most previous work repair cost is stated in terms of tuple insertions and deletions, we follow recent work to define a database repair as a set of value modifications. In this context, we introduce a novel cost framework that allows for the application of techniques from record-linkage to the search for good repairs. We prove that finding minimal-cost repairs in this model is NP-complete in the size of the database, and introduce an approach to heuristic repair-construction based on equivalence classes of attribute values. Following this approach, we define two greedy algorithms. While these simple algorithms take time cubic in the size of the database, we develop optimizations inspired by algorithms for duplicate-record detection that greatly improve scalability. We evaluate our framework and algorithms on synthetic and real data, and show that our proposed optimizations greatly improve performance at little or no cost in repair quality.

Tunable liquid microlens

Abstract: A tunable liquid microlens includes an insulating layer, a droplet of a transparent conducting liquid disposed on a first surface of the insulating layer and a plurality of electrodes insulated from the droplet by the insulating layer. The plurality of electrodes are disposed such that they may be selectively biased to create a respective voltage potential between the droplet and each of the plurality of electrodes, whereby a contact angle between the droplet and the first surface is variable and the droplet may be repositioned along the first surface.

Fabrication and properties of epitaxial ferroelectric heterostructures with (SrRuO3) isotropic metallic oxide electrodes

Abstract: Epitaxial ferroelectric SrRuO3/Pb(Zr0.52Ti0.48)O3/SrRuO3 heterostructures have been fabricated employing isotropic metallic oxide electrodes on (100) SrTiO3 and (100) Si with an yttria stabilized zirconia buffer layer. The structures have been grown in situ by 90° off‐axis sputtering, which allows the growth of uniform stoichiometric films over large areas with excellent step coverage. X‐ray diffraction, Rutherford backscattering spectroscopy, and cross‐sectional transmission electron microscopy reveal high crystalline quality and coherent interfaces. They exhibit superior fatigue characteristics over those made with metal electrodes, showing little degradation over 1010 cycles, with a large remnant polarization.

Berry Phase Theory of the Anomalous Hall Effect: Application to Colossal Magnetoresistance Manganites

Abstract: We show that the anomalous Hall effect (AHE) observed in colossal magnetoresistance manganites is a manifestation of Berry phase effects caused by carrier hopping in a nontrivial spin background. We determine the magnitude and temperature dependence of the Berry phase contribution to the AHE, finding that it increases rapidly in magnitude as the temperature is raised from zero through the magnetic transition temperature ${T}_{c}$, peaks at a temperature ${T}_{\mathrm{max}}g{T}_{c}$, and decays as a power of $T$, in agreement with experimental data. We suggest that our theory may be relevant to the anomalous Hall effect in conventional ferromagnets as well.