1,531 research outputs found

    Landau-Zener tunneling of a single Tb3+ magnetic moment allowing the electronic read-out of a nuclear spin

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    A multi-terminal device based on a carbon nanotube quantum dot was used at very low tem- perature to probe a single electronic and nuclear spin embedded in a bis-phthalocyanine Terbium (III) complex (TbPc2). A spin-valve signature with large conductance jumps was found when two molecules were strongly coupled to the nanotube. The application of a transverse field separated the magnetic signal of both molecules and enabled single-shot read-out of the Terbium nuclear spin. The Landau-Zener (LZ) quantum tunneling probability was studied as a function of field sweep rate, establishing a good agreement with the LZ equation and yielding the tunnel splitting \Delta. It was found that ? increased linearly as a function of the transverse field. These studies are an essential prerequisite for the coherent manipulation of a single nuclear spin in TbPc2.Comment: 7 pages, 6 figures, to appear in PR

    Molecular Spin Qudits for Quantum Algorithms

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    Presently, one of the most ambitious technological goals is the development of devices working under the laws of quantum mechanics. One prominent target is the quantum computer, which would allow the processing of information at quantum level for purposes not achievable with even the most powerful computer resources. The large-scale implementation of quantum information would be a game changer for current technology, because it would allow unprecedented parallelised computation and secure encryption based on the principles of quantum superposition and entanglement. Currently, there are several physical platforms racing to achieve the level of performance required for the quantum hardware to step into the realm of practical quantum information applications. Several materials have been proposed to fulfil this task, ranging from quantum dots, Bose-Einstein condensates, spin impurities, superconducting circuits, molecules, amongst others. Magnetic molecules are among the list of promising building blocks, due to (i) their intrinsic monodispersity, (ii) discrete energy levels (iii) the possibility of chemical quantum state engineering, and (iv) their multilevel characteristics, leading to the so called Qudits (d > 2), amongst others. Herein we review how a molecular multilevel nuclear spin qubit (or qudit, where d = 4), known as TbPc2, gathers all the necessary requirements to perform as a molecular hardware platform with a first generation of molecular devices enabling even quantum algorithm operations.Comment: Chem. Soc. Rev., 2017, Advance Articl

    El impacto de la crisis asi√°tica en el Cono Sur latinoamericano

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    La crisis del sudeste asi√°tico y la recesi√≥n en Jap√≥n parecieran tener un efecto directo relativamente acotado en los flujos de comercio agregados del Cono Sur, sin embargo parece ser significativo el impacto de la turbulencia en los mercados de capitales. Chile y Brasil confrontan esta situaci√≥n con d√©ficits de balanza de cuenta corriente dif√≠ciles de sostener, sin recurrir a pol√≠ticas de cambio m√°s activas, con tasas de devaluaci√≥n m√°s aceleradas, acompa√Īadas con pol√≠ticas fiscales y monetaria contractivas para evitar repuntes inflacionarios. Por su parte, la econom√≠a argentina evidencia, una vez m√°s, su capacidad de mantener la convertibilidad del peso a√ļn en situaciones de fuerte recesi√≥n, cuya profundidad depender√° de dos factores: las posibilidades de acceso a capitales internacionales, y de la evoluci√≥n del plan de estabilizaci√≥n brasile√Īo.

    Sublimable Spin Crossover Complexes: From Spin-State Switching to Molecular Devices

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    Spin‚Äźcrossover (SCO) active transition metal complexes are an important class of switchable molecular materials due to their bistable spin‚Äźstate switching characteristics at or around room temperature. Vacuum‚Äźsublimable SCO complexes are a subclass of SCO complexes suitable for fabricating ultraclean spin‚Äźswitchable films desirable for applications, especially in molecular electronics/spintronics. Consequently, on‚Äźsurface SCO of thin‚Äźfilms of sublimable SCO complexes have been studied employing spectroscopy and microscopy techniques, and results of fundamental and technological importance have been obtained. This Review provides complete coverage of advances made in the field of vacuum‚Äźsublimable SCO complexes: progress made in the design and synthesis of sublimable functional SCO complexes, on‚Äźsurface SCO of molecular and multilayer thick films, and various molecular and thin‚Äźfilm device architectures based on the sublimable SCO complexes

    Estímulos de la inversión extrajera directa sobre empresas nacionales

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    This paper examines spillovers from FDI in Uruguayan manufacturing firms to determine whether foreign presence has any impact on the levels of labor productivity in local firms. We find a positive and statistically significant spillover effects in the whole sample, with a stronger impact of foreign presence on the performance of small firms. We also find positive and statiscally significant spillover effects when the organizational gap between foreign and local firms is moderate and when the technology gap is large. Our interpretation is that there are firm-specific differences in the ability to absorb spillovers.

    Redescription of Biturix rectilinea(Burmeister, 1878) with comments on its taxonomic position(Lepidoptera: Erebidae, Arctiinae)

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    Se redescribe a Biturix rectilinea(Burmeister, 1878) de Argentina. Se designa un Lectotipo. Por primeravez se describen e ilustran los genitalia de ambos sexos. Caracteres de la genitalia y los coremata abdominalesen el macho apoyan su pertenencia al grupo Euchaetesde Phaegopterina.Biturix rectilinea(Burmeister, 1878) from Argentina is redescribed. A Lectotype is designated. For thefirst time, male and female genitalia are described and illustrated. Characters of male genitalia and maleabdominal coremata support its belonging to the Euchaetesgroup of Phaegopterina.Fil: Beccacece, Hernán Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Navarro, Fernando Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentin

    Nuevas citas de √°rctidos para la Argentina (Lepidoptera: Erebidae, Arctiinae)

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    Twenty four new records of arctiid moths for Argentina are presented.Se presentan un total de veinticuatro nuevas citas de árctidos para ArgentinaFil: Beccacece, Hernán Mario. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones Entomológicas de Córdoba; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas, Argentina;Fil: Navarro, Fernando Ruben. Fundación Miguel Lillo. Dirección de Zoología; Argentina; Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentina

    Solvent-Induced Polymorphism of Iron(II) Spin Crossover Complexes

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    Two new mononuclear iron(II) compounds (1) and (2) of the general formula [Fe(L) 2_{2}](BF4_{4})2_{2}·nCH3_{3}CN (L = 4-(2-bromoethyn-1-yl)-2,6-bis(pyrazol-1-yl)pyridine, n = 1 for (1) and n = 2 for compound (2)), were synthesized. The room temperature crystallization afforded concomitant formation of two different solvent analogues: compound (1) exhibiting triclinic P-1 and compound (2) monoclinic C2/c symmetry. Single-crystal X-ray studies confirmed the presence of the LS (low-spin) state for both compounds at 180 K and of the HS (high-spin) state for compound (2) at 293 K, in full agreement with the magnetic investigations for both solvent polymorphs. Compound (1) exhibits spin transition above 293 K followed by subsequent solvent liberation, while the spin transition of (2) takes already place at 237 K. After complete solvent removal from the crystal lattice, compound (1d) (the desolvated polymorph derived from (1)) exhibits spin transition centered at 342 K accompanied by a thermal hysteresis loop, while the analogous compound (2d) (the desolvated derivate of compound (2)) remains blocked in the HS state over all the investigated temperature range
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