487 research outputs found
Entropic Entanglement Criteria for Continuous Variables
We derive several entanglement criteria for bipartite continuous variable
quantum systems based on the Shannon entropy. These criteria are more sensitive
than those involving only second-order moments, and are equivalent to
well-known variance product tests in the case of Gaussian states. Furthermore,
they involve only a pair of quadrature measurements, and will thus should prove
extremely useful the experimental identification of entanglement.Comment: 4 pages, 2 figure
Isolamento de um inibidor de tripsina de sementes de Hymenaea courbaril Lee & Langenh por cromatografia de troca iônica.
Caracterização de uma amilase de sementes de Libidibia ferrea (Mart. ex. Tul.).
Caracterizar uma amilase de extratos aquosos de sementes de L. ferrea quanto à estabilidade térmica e massa molecular
Inibidores de papaina e tripsina em frações proteicas de sementes de Libidibia ferrea (Mart. ex Tul.).
Verificar a inibição da papaína e da tripsina por frações protéicas de sementes de Libidibia ferreae seu perfil eletroforético
Ensaio alternativo para triagem de extratos protéicos com atividade celulolítica.
Este comunicado apresenta uma metodologia de difusão radial em gel de agarose (DRGA) desenvolvida por Teather e Wood (1982), modificada por Rehman et al. (2009), e adaptada no Laboratório de Bioquímica da Embrapa Caprinos e Ovinos para avaliar a atividade celulolítica em extratos proteicos de microrganismos ruminais. A técnica baseia-se na difusão radial, em gel de agarose, das proteínas da amostra analisada. O gel contém o substrato específico para celulase, a carboximetilcelulose, que pode ser corada com o corante vermelho congo.bitstream/item/31686/1/UMT-Cot112.pd
Experimental investigation of the dynamics of entanglement: Sudden death, complementarity, and continuous monitoring of the environment
We report on an experimental investigation of the dynamics of entanglement
between a single qubit and its environment, as well as for pairs of qubits
interacting independently with individual environments, using photons obtained
from parametric down-conversion. The qubits are encoded in the polarizations of
single photons, while the interaction with the environment is implemented by
coupling the polarization of each photon with its momentum. A convenient Sagnac
interferometer allows for the implementation of several decoherence channels
and for the continuous monitoring of the environment. For an
initially-entangled photon pair, one observes the vanishing of entanglement
before coherence disappears. For a single qubit interacting with an
environment, the dynamics of complementarity relations connecting single-qubit
properties and its entanglement with the environment is experimentally
determined. The evolution of a single qubit under continuous monitoring of the
environment is investigated, demonstrating that a qubit may decay even when the
environment is found in the unexcited state. This implies that entanglement can
be increased by local continuous monitoring, which is equivalent to
entanglement distillation. We also present a detailed analysis of the transfer
of entanglement from the two-qubit system to the two corresponding
environments, between which entanglement may suddenly appear, and show
instances for which no entanglement is created between dephasing environments,
nor between each of them and the corresponding qubit: the initial two-qubit
entanglement gets transformed into legitimate multiqubit entanglement of the
Greenberger-Horne-Zeilinger (GHZ) type.Comment: 15 pages, 14 figures; only .ps was working, now .pdf is also
availabl
Cloning, purification, and partial characterization of Bacillus subtilis urate oxidase expressed in Escherichia coli.
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