2,998 research outputs found
Multipartite entangled states with two bosonic modes and qubits
We theoretically investigate the role of different phases of coupling
constants in the dynamics of atoms and two cavity modes, observing
deterministic generation of prototype or hybrid Bell, W, GHZ, and cluster
states. Commonly induced dipole-dipole interactions (far-off resonance) are
inhibited between particular pairs of qubits under suitable choice of those
phases. We evaluate the generation fidelities when imperfections such as
dissipative environments and time precision errors are considered. We show
violation of local realism for the generated cluster state under such
imperfections, even when approaching the weak coupling regime.Comment: 10 pages, 5 figures, REVTeX 4.1, BibTeX, final versio
Phylogenetic analysis of Infectious Bursal Diseases Virus in South Brazil.
Projeto/Plano de Ação: 02.09.01.030
NUMERICAL STUDY OF COOLING BY TANGENTIAL SYNTHETIC JET
Modern electronics are becoming more compact and with higher processing power, which translates into a demand for higher heat dissipation. Current electronic "coolers," which are based on the combination of fans and heat sinks, are becoming unable to provide sufficient heat dissipation since they rely primarily on generating large volumetric flowrates of air to achieve their results. As an alternative, synthetic jets are under consideration due to their known property to enhance turbulence and heat transfer. Synthetic jets are produced by the oscillation of a membrane in a sealed cavity equipped with an orifice. For this study, a numerical model of channel mounted with a heating element on one surface and a synthetic jet directed to blow along the wall was constructed on ANSYS CFX. Heat dissipation provided by the synthetic jet was analyzed with respect to changes in Reynolds number, pulsing frequency and placement of the heated element. Results were compared to a conventional technique represented by a steady channel flow of equivalent mass flow rate to the average flow induced by the synthetic jet. Results showed that the synthetic jet formed a thin layer of intense vorticity along the targeted surface with cooling greatly outperforming conventional techniques. Synthetic jet cooling was also determined to be most affected by jet velocity and Reynolds number while pulsing frequency and placement of the heated element were not as influential
Spontaneous emission and teleportation in cavity QED
In this work, we consider atomic spontaneous emission in a system consisting
of two identical two-level atoms interacting dispersively with the quantized
electromagnetic field in a high-Q cavity. We investigate the destructive effect
of the atomic decay on the generation of maximally entangled states, following
the proposal by Zheng S B and Guo G C (2000 Phys. Rev. Lett. 85 2392). In
particular, we analyze the fidelity of teleportation performed using such a
noisy channel and calculatethe maximum spontaneous decay rate we may have in
order to realize teleportation.Comment: 11 pages, 6 figures, LaTe
Bipartite quantum channels using multipartite cluster-type entangled coherent states
We propose a particular encoding for bipartite entangled states derived from
multipartite cluster-type entangled coherent states (CTECSs). We investigate
the effects of amplitude damping on the entanglement content of this bipartite
state, as well as its usefulness as a quantum channel for teleportation. We
find interesting relationships among the amplitude of the coherent states
constituting the CTECSs, the number of subsystems forming the logical qubits
(redundancy), and the extent to which amplitude damping affects the
entanglement of the channel. For instance, in the sense of sudden death of
entanglement, given a fixed value of the initial coherent state amplitude, the
entanglement life span is shortened if redundancy is increased.Comment: 6 pages, 3 figures, REVTeX 4.1, BibTe
In vivo assay of vaccine protection to Brazilian variant strains of infectious bronchitis vírus.
Projeto/Plano de Ação: 03.09.00.018
Comparação entre a concentração atmosférica de Phl p5 e as contagens polínicas de gramíneas
A exposição a alergenos de gramíneas é actualmente calculada a partir de contagens polínicas dos respectivos tipos polínicos, efectuadas em amostras de ar atmosférico segundo uma metodologia normalizada e assente em equipamentos tipo HIRST. Não existe ainda suficiente evidência de que tais contagens representem uma boa estimativa da exposição aos aeroalergenos deste tipo polínico pelo que, neste estudo, se procurou analisar a relação entre tais contagens e a concentração de um dos alergenos polínicos mais importantes
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