Generation of decoherence-free displaced squeezed states of radiation fields and a squeezed reservoir for atoms in cavity QED

We present a way to engineer an effective anti-Jaynes-Cumming and a Jaynes-Cumming interaction between an atomic system and a single cavity mode and show how to employ it in reservoir engineering processes. To construct the effective Hamiltonian, we analyse considered the interaction of an atomic system in a \{Lambda} configuration, driven by classical fields, with a single cavity mode. With this interaction, we firstly show how to generate a decoherence-free displaced squeezed state for the cavity field. In our scheme, an atomic beam works as a reservoir for the radiation field trapped inside the cavity, as employed recently by S. Pielawa et al. [Phys. Rev. Lett. 98, 240401 (2007)] to generate an Einstein-Podolsky-Rosen entangled radiation state in high-Q resonators. In our scheme, all the atoms have to be prepared in the ground state and, as in the cited article, neither atomic detection nor precise interaction times between the atoms and the cavity mode are required. From this same interaction, we can also generate an ideal squeezed reservoir for atomic systems. For this purpose we have to assume, besides the engineered atom-field interaction, a strong decay of the cavity field (i.e., the cavity decay must be much stronger than the effective atom-field coupling). With this scheme, some interesting effects in the dynamics of an atom in a squeezed reservoir could be tested

Parâmetros microbiológicos de carcaças suínas amostradas na etapa de pré-resfriamento.

Projeto/Plano de Ação: 11.11.11.111

Detection of salmonella heidelberg resistant to colistin in the intestinal content of pigs at slaughter.

Abstract : Salmonella Heidelberg has increasingly been reported as cause of human salmonellosis worldwide. In Brazil, S. Heidelberg has been reported in poultry but it is infrequently isolated from pigs. Here, we describe the isolation of S. Heidelberg resistant to colistin from slaughter pigs. Five pigs and their carcasses belonging to a same slaughter batch in ten consecutive days were sampled for fragment of intestine in the ileocecal region and sponges rubbed on the carcass surface (400 cm2 ) before chilling. Salmonella detection was performed according to the ISO 6579:2002. Intestinal content was also subjected to Salmonella enumeration by a miniaturized Most Probable Number (MPN) protocol. Salmonella isolates were characterized by antimicrobial resistance by the disk diffusion test, the minimum inhibitory concentration to colistin determination and to gene mcr-1 investigation by PCR. Salmonella was isolated from the intestinal content of 64% (32/50) of the pigs, in amounts that varied from 2.7 to >1,400 MPN/g. Salmonella Heidelberg was the most frequent serovar identified in the intestinal content samples (20/50; 40%), and this serovar was present in eight of the ten pig batches sampled. At the prechill, Salmonella was isolated from 8% of carcasses, and S. Heidelberg was not detected. Salmonella Heidelberg strains were resistant against ampicillin (n=9), tetracycline (n=8), sulfonamide (n=8) and gentamicin (n=5). Nine multi-drug resistant strains were detected; among them four strains were positive for the gene mcr-1. In these strains the MIC value was 8 µg.mL-1 , while in the strains without the mcr-1 gene it ranged from 2 µg.mL-1 to 4 µg.mL-1 . Therefore, humans in contact with carrier pigs or their environment may be exposed to S. Heidelberg, including strains harboring the gene mcr-1.SafePork 2017

A MEDIAÇÃO NO ÂMBITO DA ECOLOGIA POLÍTICA

A ocorrência de um crime se dá quando há a subsunção de um determinado fato a um tipo legal que prevê uma conduta como delituosa. Ou seja, a análise de uma infração penal se dá estritamente em termos legais, não havendo uma perquirição de questões familiares e comunitárias, o que, na pós-modernidade, se torna necessário para efetiva resolução dos conflitos. Assim, o objetivo do presente texto é examinar os benefícios que a mediação pode trazer como efetiva forma de resolução de conflitos, o que pode ocorrer inclusive na esfera penal, buscando construir a ecologia dos vínculos, da ética, do direito, possibilitando a melhora da qualidade de vida, viabilizando-se um método no qual a aplicação coercitiva e terceirizada à Justiça Estatal cede lugar para um procedimento que tende à satisfação de desejos e à ampliação de responsabilidades entre as pessoas envolvidas em conflito

Algebraic characterization of X-states in quantum information

A class of two-qubit states called X-states are increasingly being used to discuss entanglement and other quantum correlations in the field of quantum information. Maximally entangled Bell states and "Werner" states are subsets of them. Apart from being so named because their density matrix looks like the letter X, there is not as yet any characterization of them. The su(2) X su(2) X u(1) subalgebra of the full su(4) algebra of two qubits is pointed out as the underlying invariance of this class of states. X-states are a seven-parameter family associated with this subalgebra of seven operators. This recognition provides a route to preparing such states and also a convenient algebraic procedure for analytically calculating their properties. At the same time, it points to other groups of seven-parameter states that, while not at first sight appearing similar, are also invariant under the same subalgebra. And it opens the way to analyzing invariant states of other subalgebras in bipartite systems.Comment: 4 pages, 1 figur

Geometric measure of quantum discord and the geometry of a class of two-qubit states

We investigate the geometric picture of the level surfaces of quantum entanglement and geometric measure of quantum discord (GMQD) of a class of X-states, respectively. This pictorial approach provides us a direct understanding of the structure of entanglement and GMQD. The dynamic evolution of GMQD under two typical kinds of quantum decoherence channels is also investigated. It is shown that there exists a class of initial states for which the GMQD is not destroyed by decoherence in a finite time interval. Furthermore, we establish a factorization law between the initial and final GMQD, which allows us to infer the evolution of entanglement under the influences of the environment.Comment: 10 pages, 4 figures, comments are welcom

Overview on the phenomenon of two-qubit entanglement revivals in classical environments

The occurrence of revivals of quantum entanglement between separated open quantum systems has been shown not only for dissipative non-Markovian quantum environments but also for classical environments in absence of back-action. While the phenomenon is well understood in the first case, the possibility to retrieve entanglement when the composite quantum system is subject to local classical noise has generated a debate regarding its interpretation. This dynamical property of open quantum systems assumes an important role in quantum information theory from both fundamental and practical perspectives. Hybrid quantum-classical systems are in fact promising candidates to investigate the interplay among quantum and classical features and to look for possible control strategies of a quantum system by means of a classical device. Here we present an overview on this topic, reporting the most recent theoretical and experimental results about the revivals of entanglement between two qubits locally interacting with classical environments. We also review and discuss the interpretations provided so far to explain this phenomenon, suggesting that they can be cast under a unified viewpoint.Comment: 16 pages, 9 figures. Chapter written for the upcoming book "Lectures on general quantum correlations and their applications