Detection of Multiparticle Entanglement: Quantifying the Search for Symmetric Extensions

We provide quantitative bounds on the characterisation of multiparticle separable states by states that have locally symmetric extensions. The bounds are derived from two-particle bounds and relate to recent studies on quantum versions of de Finetti's theorem. We discuss algorithmic applications of our results, in particular a quasipolynomial-time algorithm to decide whether a multiparticle quantum state is separable or entangled (for constant number of particles and constant error in the LOCC or Frobenius norm). Our results provide a theoretical justification for the use of the Search for Symmetric Extensions as a practical test for multiparticle entanglement.Comment: 5 pages, 1 figur

Propagation of Partially Coherent Light in non-Hermitian Lattices

Band theory for partially coherent light is introduced by using the formalism of second-order classical coherence theory under paraxial approximation. It is demonstrated that the cross-spectral density function, describing correlations between pairs of points in the field, can have bands and gaps and form a correlation band structure. The propagation of a partially coherent beam in non-Hermitian periodic structures is considered to elucidate the interplay between the degree of coherence and the gain/loss present in the lattice. We apply the formalism to study partially coherent Bloch oscillations in lattices having parity-time symmetry and demonstrate that the oscillations can be sustained in such media but they are strongly dependent upon the spatial correlations of the beam. A transition between breathing and oscillating modes is shown to be induced by the degree of spatial coherence

Mapping mass customization

Mass customization (MC) and personal fabrication (PF) are current relevant topics in architecture offices practice and schools design research. Architects are adopting information based design and production techniques as a response to architectural century challenges. However, is not clear how various authors used and transformed the concept in practice, research and industry after three decades since the MC term was introduced by Davis (1987). Therefore, is essential to map the most relevant works in the field in relation to production and design control. The paper presents some of the results of the ongoing study through an evolving map that aims to visualize relationships, layering complexity and revealing difference.info:eu-repo/semantics/publishedVersio

The quantum one-time pad in the presence of an eavesdropper

A classical one-time pad allows two parties to send private messages over a public classical channel -- an eavesdropper who intercepts the communication learns nothing about the message. A quantum one-time pad is a shared quantum state which allows two parties to send private messages or private quantum states over a public quantum channel. If the eavesdropper intercepts the quantum communication she learns nothing about the message. In the classical case, a one-time pad can be created using shared and partially private correlations. Here we consider the quantum case in the presence of an eavesdropper, and find the single letter formula for the rate at which the two parties can send messages using a quantum one-time pad

Quantifying Quantum Correlations in Fermionic Systems using Witness Operators

We present a method to quantify quantum correlations in arbitrary systems of indistinguishable fermions using witness operators. The method associates the problem of finding the optimal entan- glement witness of a state with a class of problems known as semidefinite programs (SDPs), which can be solved efficiently with arbitrary accuracy. Based on these optimal witnesses, we introduce a measure of quantum correlations which has an interpretation analogous to the Generalized Robust- ness of entanglement. We also extend the notion of quantum discord to the case of indistinguishable fermions, and propose a geometric quantifier, which is compared to our entanglement measure. Our numerical results show a remarkable equivalence between the proposed Generalized Robustness and the Schliemann concurrence, which are equal for pure states. For mixed states, the Schliemann con- currence presents itself as an upper bound for the Generalized Robustness. The quantum discord is also found to be an upper bound for the entanglement.Comment: 7 pages, 6 figures, Accepted for publication in Quantum Information Processin

Letter to the editor

info:eu-repo/semantics/publishedVersio

Mosaico de imagens de satélite do Pantanal no ano 2000.

O Pantanal devido a sua extensão e dificuldade de acesso representa um desafio para o desenvolvimento de atividades de produção e conservação da natureza. Nesse sentido as tecnologias de Sensoriamento Remoto podem contribuir muito para o conhecimento e manejo desse ecossistema. O presente trabalho apresenta o mosaico de imagens Landsat 7 ETM do ano 2000 do Pantanal, onde ao contrário dos demais produtos dessa natureza, apresenta uma maior precisão de posicionamento em função de um extenso trabalho de campo realizado para o georreferenciamento das imagens. Esse trabalho é o resultado da parceria entre a Embrapa Pantanal e a WWF Brasil e está disponível também na homepage da Embrapa Pantanal. Esperamos com essa iniciativa estar cumprindo com nosso objetivo de levar à comunidade informações sobre o Pantanal.bitstream/item/81191/1/DOC43.pd

Adubação química de cultivares de pimenta-do-reino (Piper nigrum L.) em latossolo amarelo da rodovia Transamazônica.

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