4,912 research outputs found
Entanglement Equivalence of -qubit Symmetric States
We study the interconversion of multipartite symmetric -qubit states under
stochastic local operations and classical communication (SLOCC). We demonstrate
that if two symmetric states can be connected with a nonsymmetric invertible
local operation (ILO), then they belong necessarily to the separable, W, or GHZ
entanglement class, establishing a practical method of discriminating subsets
of entanglement classes. Furthermore, we prove that there always exists a
symmetric ILO connecting any pair of symmetric -qubit states equivalent
under SLOCC, simplifying the requirements for experimental implementations of
local interconversion of those states.Comment: Minor correction
Observations complementaires sur le polymorphisme enzymatique d'<i>Electra pilosa</i> et d<i>E. verticillata</i> (Bryozoaires Cheilostomes)
A Geometrical Representation of Entanglement as Internal Constraint
We study a system of two entangled spin 1/2, were the spin's are represented
by a sphere model developed within the hidden measurement approach which is a
generalization of the Bloch sphere representation, such that also the
measurements are represented. We show how an arbitrary tensor product state can
be described in a complete way by a specific internal constraint between the
ray or density states of the two spin 1/2. We derive a geometrical view of
entanglement as a 'rotation' and 'stretching' of the sphere representing the
states of the second particle as measurements are performed on the first
particle. In the case of the singlet state entanglement can be represented by a
real physical constraint, namely by means of a rigid rod.Comment: 10 pages, 3 figures. submitted to International Journal of
Theoretical Physic
Multipartite entanglement in the Fenna-Matthews-Olson (FMO) pigment-protein complex
We investigate multipartite states in the Fenna-Matthews-Olson (FMO)
pigment-protein complex of the green sulfur bacteria using a Lorentzian
spectral density of the phonon reservoir fitted with typical parameter
estimates of the species, P. aestuarii. The evolution of the entanglement
measure of the excitonic W qubit states is evaluated in the picosecond time
range, showing increased revivals in the non-Markovian regime. Similar trends
are observed in the evolution dynamics of the Meyer-Wallach measure of the
N-exciton multipartite state, with results showing that multipartite
entanglement can last from 0.5 to 1 ps, between the Bchls of the FMO complex.
The teleportation and quantum information splitting fidelities associated with
the GHZ and W_A resource states of the excitonic qubit channels of the FMO
complex show that revivals in fidelities increase with the degree of
non-Markovian strength of the decoherent environment. Results indicate that
quantum information processing tasks involving teleportation followed by the
decodification process involving W_A states of the FMO complex, may play a
critical role during coherent oscillations at physiological temperatures.Comment: 16 pages, new figs, typo
Environmental justice in Halmahera Utara: lost in poverty, interests and identity
Effective Protection of Fundamental Rights in a pluralist worl
The Measurement Calculus
Measurement-based quantum computation has emerged from the physics community
as a new approach to quantum computation where the notion of measurement is the
main driving force of computation. This is in contrast with the more
traditional circuit model which is based on unitary operations. Among
measurement-based quantum computation methods, the recently introduced one-way
quantum computer stands out as fundamental.
We develop a rigorous mathematical model underlying the one-way quantum
computer and present a concrete syntax and operational semantics for programs,
which we call patterns, and an algebra of these patterns derived from a
denotational semantics. More importantly, we present a calculus for reasoning
locally and compositionally about these patterns.
We present a rewrite theory and prove a general standardization theorem which
allows all patterns to be put in a semantically equivalent standard form.
Standardization has far-reaching consequences: a new physical architecture
based on performing all the entanglement in the beginning, parallelization by
exposing the dependency structure of measurements and expressiveness theorems.
Furthermore we formalize several other measurement-based models:
Teleportation, Phase and Pauli models and present compositional embeddings of
them into and from the one-way model. This allows us to transfer all the theory
we develop for the one-way model to these models. This shows that the framework
we have developed has a general impact on measurement-based computation and is
not just particular to the one-way quantum computer.Comment: 46 pages, 2 figures, Replacement of quant-ph/0412135v1, the new
version also include formalization of several other measurement-based models:
Teleportation, Phase and Pauli models and present compositional embeddings of
them into and from the one-way model. To appear in Journal of AC
Obesity and motor skills among 4 to 6-year-old children in the united states: nationally-representative surveys
Few population-based studies have assessed relationships between body weight and motor skills in young children. Our objective was to estimate the association between obesity and motor skills at 4 years and 5-6 years of age in the United States. We used repeated cross-sectional assessments of the national sample from the Early Childhood Longitudinal Survey-Birth Cohort (ECLS-B) of preschool 4-year-old children (2005-2006; n = 5 100) and 5-6-year-old kindergarteners (2006-2007; n = 4 700). Height, weight, and fine and gross motor skills were assessed objectively via direct standardized procedures. We used categorical and continuous measures of body weight status, including obesity (Body Mass Index (BMI) ≥ 95th percentile) and BMI z-scores. Multivariate logistic and linear models estimated the association between obesity and gross and fine motor skills in very young children adjusting for individual, social, and economic characteristics and parental involvement.info:eu-repo/semantics/publishe
Fauna Europaea: Gastrotricha.
Fauna Europaea provides a public web-service with an index of scientific names (including
important synonyms) of all living European land and freshwater animals, their geographical
distribution at country level (up to the Urals, excluding the Caucasus region), and some
additional information. The Fauna Europaea project covers about 230,000 taxonomic
names, including 130,000 accepted species and 14,000 accepted subspecies, which is
much more than the originally projected number of 100,000 species. This represents a
huge effort by more than 400 contributing specialists throughout Europe and is a unique
(standard) reference suitable for many users in science, government, industry, nature
conservation and education
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