Low frequency noise due to magnetic inhomogeneities in submicron FeCoB/MgO/FeCoB magnetic tunnel junctions

We report on room temperature low frequency noise due to magnetic inhomogeneities/domain walls (MI/DWs) in elliptic submicron FeCoB/MgO/FeCoB magnetic tunnel junctions with an area between 0.0245 and 0.0675{\mu}m2. In the smaller area junctions we found an unexpected random telegraph noise (RTN1), deeply in the parallel state, possibly due to stray field induced MI/DWs in the hard layer. The second noise source (RTN2) is observed in the antiparallel state for the largest junctions. Strong asymmetry of RTN2 and of related resistance steps with current indicate spin torque acting on the MI/DWs in the soft layer at current densities below 5x10^5 A/cm2.Comment: 12 pages, 4 figure

Broadband probing magnetization dynamics of the coupled vortex state permalloy layers in nanopillars

Broadband magnetization response of coupled vortex state magnetic dots in layered nanopillars was explored as a function of in-plane magnetic field and interlayer separation. For dipolarly coupled circular Py(25 nm)/Cu(20 nm)/Py(25 nm) nanopillars of 600 nm diameter, a small in-plane field splits the eigenfrequencies of azimuthal spin wave modes inducing an abrupt transition between in-phase and out-of-phase kinds of the low-lying coupled spin wave modes. The critical field for this splitting is determined by antiparallel chiralities of the vortices in the layers. Qualitatively similar (although more gradual) changes occur also in the exchange coupled Py(25 nm)/Cu(1 nm)/Py(25 nm) tri-layer nanopillars. These findings are in qualitative agreement with micromagnetic dynamic simulations

Isotopic replacement in ionic systems: the 4He2+ + 3He -> 3He4He+ + 4He reaction

Full quantum dynamics calculations have been carried out for the ionic reaction 4He2+ + 3He and state-to-state reactive probabilities have been obtained using both a time-dependent (TD) and a time-independent (TI) approach. An accurate ab-initio potential energy surface has been employed for the present quantum dynamics and the two sets of results are shown to be in agreement with each other. The results for zero total angular momentum suggest a marked presence of atom exchange (isotopic replacement) reaction with probabilities as high as 60%. The reaction probabilities are only weakly dependent on the initial vibrational state of the reactants while they are slightly more sensitive to the degree of rotational excitation. A brief discussion of the results for selected higher total angular momentum values is also presented, while the l-shifting approximation [1] has been used to provide estimates of the total reaction rates for the title process. Such rates are found to be large enough to possibly become experimentally accessible

Quantum entanglement and classical communication through a depolarising channel

We analyse the role of entanglement for transmission of classical information through a memoryless depolarising channel. Using the isotropic character of this channel we prove analytically that the mutual information cannot be increased by encoding classical bits into entangled states of two qubits.Comment: 6 pages, 2 figures; contribution to special issue of JMO on the physics of quantum information; 2nd version: slight modifications and improved presentatio

VLBI Observations of a Complete Sample of Radio Galaxies V. 3C346 and 4C31.04: two Unusual CSS Sources

We present observations at 1.7 and 8.4 GHz of two Compact Steep Spectrum (CSS) sources from a complete sample of low-intermediate power radio galaxies. 3C346 shows an asymmetric structure with a one-sided ``jet'' and ``hot spot''. Present observations suggest that the classification of this source as a CSS is inappropriate, and that it is a common radio galaxy at a small angle to the line of sight. Its properties are in agreement with the predictions of unified schemes models. 4C31.04 shows more complex structure with the possibility of a centrally located flat spectrum core in between two close lobes. We suggest that this source could be a low redshift Compact Symmetric Object.Comment: 15 pages, LATEX, uuenconde ps figures To be published in the Astrophysical Journal, October 20th issu

Características físicas da carne de queixada (Tayassu pecari Link, 1795).

A fauna é um agente que não pode ser ignorado na gestão de recursos naturais renováveis. Além de sua importância direta na conservação dos ecossistemas, o desenvolvimento do potencial econômico das espécies silvestres pode viabilizar, em curto prazo, a conservação de tais organismos também de ecossistemas. Este estudo descreve características físicas da carne de queixa das (Tayassu pecari) produzidas em cativeiro. Quinze animais (seis machos e nove fêmeas) criados no município de Mineiros-GO foram abatidos em frigorífico de Formosa-GO, em novembro de 2007. Os parâmetros considerados foram: queda do pH 24h após o abate, perdas por cozimento (PPC) e capacidade de retenção de água (CRA) do músculo Longissimus dorsi. O pH médio foi de 6,20, as perdas por cozimento foram em média de 21,57 % e a capacidade de retenção de água média foi de 68,80 %. Não houve diferença entre sexos. Os resultados demonstram que a carne de queixada oriunda de cativeiro apresenta valores semelhantes aos de outras espécies. Observou-se, no entanto, que o percurso de 700 km (9 horas) que precedeu o abate pode ter influenciado os resultados observados