Optimal minimal measurements of mixed states

The optimal and minimal measuring strategy is obtained for a two-state system prepared in a mixed state with a probability given by any isotropic a priori distribution. We explicitly construct the specific optimal and minimal generalized measurements, which turn out to be independent of the a priori probability distribution, obtaining the best guesses for the unknown state as well as a closed expression for the maximal mean averaged fidelity. We do this for up to three copies of the unknown state in a way which leads to the generalization to any number of copies, which we then present and prove.Comment: 20 pages, no figure

Zero dimensional area law in a gapless fermion system

The entanglement entropy of a gapless fermion subsystem coupled to a gapless bulk by a "weak link" is considered. It is demonstrated numerically that each independent weak link contributes an entropy proportional to lnL, where L is linear dimension of the subsystem.Comment: 6 pages, 11 figures; added 3d computatio

Complex symplectic lie algebras with large abelian subalgebras

We present two constructions of complex symplectic structures on Lie algebras with large Abelian ideals. In particular, we completely classify complex symplectic structures on almost Abelian Lie algebras. By considering compact quotients of their corresponding connected, simply connected Lie groups we obtain many examples of complex symplectic manifolds which do not carry (hyper)kähler metrics. We also produce examples of compact complex symplectic manifolds endowed with a fibration whose fibers are Lagrangian tori

Entanglement in Valence-Bond-Solid States

This article reviews the quantum entanglement in Valence-Bond-Solid (VBS) states defined on a lattice or a graph. The subject is presented in a self-contained and pedagogical way. The VBS state was first introduced in the celebrated paper by I. Affleck, T. Kennedy, E. H. Lieb and H. Tasaki (abbreviation AKLT is widely used). It became essential in condensed matter physics and quantum information (measurement-based quantum computation). Many publications have been devoted to the subject. Recently entanglement was studied in the VBS state. In this review we start with the definition of a general AKLT spin chain and the construction of VBS ground state. In order to study entanglement, a block subsystem is introduced and described by the density matrix. Density matrices of 1-dimensional models are diagonalized and the entanglement entropies (the von Neumann entropy and Renyi entropy) are calculated. In the large block limit, the entropies also approach finite limits. Study of the spectrum of the density matrix led to the discovery that the density matrix is proportional to a projector.Comment: Published version, 80 pages, 8 figures; references update

Entanglement in a Valence-Bond-Solid State

We study entanglement in Valence-Bond-Solid state. It describes the ground state of Affleck, Kennedy, Lieb and Tasaki quantum spin chain. The AKLT model has a gap and open boundary conditions. We calculate an entropy of a subsystem (continuous block of spins). It quantifies the entanglement of this block with the rest of the ground state. We prove that the entanglement approaches a constant value exponentially fast as the size of the subsystem increases. Actually we proved that the density matrix of the continuous block of spins depends only on the length of the block, but not on the total size of the chain [distance to the ends also not essential]. We also study reduced density matrices of two spins both in the bulk and on the boundary. We evaluated concurrencies.Comment: 4pages, no figure

A MOS-based Dynamic Memetic Differential Evolution Algorithm for Continuous Optimization: A Scalability Test

Continuous optimization is one of the areas with more activity in the field of heuristic optimization. Many algorithms have been proposed and compared on several benchmarks of functions, with different performance depending on the problems. For this reason, the combination of different search strategies seems desirable to obtain the best performance of each of these approaches. This contribution explores the use of a hybrid memetic algorithm based on the multiple offspring framework. The proposed algorithm combines the explorative/exploitative strength of two heuristic search methods that separately obtain very competitive results. This algorithm has been tested with the benchmark problems and conditions defined for the special issue of the Soft Computing Journal on Scalability of Evolutionary Algorithms and other Metaheuristics for Large Scale Continuous Optimization Problems. The proposed algorithm obtained the best results compared with both its composing algorithms and a set of reference algorithms that were proposed for the special issue

Characteristics of the channels and blood parameters of chickens complemented with chromium and their productive acting

P?ginas 15-19Recurso Electr?nicoEl presente trabajo evalu? el efecto del cromo en dietas para pollo de engorde con diferentes niveles de inclusi?n. Se evalu? : peso inicial, peso final, ganancia de peso, conversi?n, consumo, rendimiento en canal, peso de alas, pechuga, pernil, colesterol, glicemia y HDL. Se emplearon 96 aves distribuidas en 4 tratamientos con 4 repeticiones y 6 aves en cada una, alimentadas con cromo a partir del d?a noveno de vida hasta el d?a 35. Los tratamientos 1, 2, 3, y 4 conten?an cromo en 0ppm, 0,5 ppm, 1 ppm, y 1,5 ppm en la dieta respectivamente. No se encontraron diferencias significativas (p0,05) en el consumo de alimento. Pese a lo anterior los mejores resultados obtenidos se presentaron en los tratamientos 2. Peso final (1983.3 g vs 2032,3 g), ganancia de peso (1811,9 g vs 1859,9 g ), conversi?n (1,666 vs 1,670). Con respecto al consumo el tratamiento control presento consumo m?s bajo (3305 g vs 3395 g), y rendimiento en canal el tratamiento control presento mejor rendimiento con respecto a los dem?s tratamientos (71,8 % vs 71,3 %). Con respecto a los cortes los resultados favorecen a los tratamientos con cromo, alas (172,9 g vs 181,5 g), pechugas (536,3 g vs 545,1 g), perniles (699,1 g vs 708,6 g). Se determin? que el tratamiento 2 presenta los mejores resultados econ?micos.ABSTRACT. This project aims to evaluate the effect of chromium in breeding chicken diets with different inclusion levels. The items evaluated were: initial weight, final weight, increase in weight, conversion, consumptions, carcass development, wings, breasts, and legs weight, cholesterol, blood sugar, and HDL. A sample of 96 birds was used distributed in 4 treatments with 4 repetitions and 6 birds each, fed with chromium since the 9th day of life until day 35. Treatments 1, 2, 3 and 4 had chromium concentrations of 0 ppm, 0,5 ppm, 1 ppm, and 1,5 ppm in their diet respectively. No significant differences were found (p0,05) was food consumption. Nevertheless, the best results were found in birds subjected to treatment 2: Final weight (1983,3 g vs. 2032,3 g), increase in weight (1811,9 g vs. 1859,9 g), and conversion (1.666 vs. 1.670). Regarding consumption, the control treatment presented the lowest rate (3305 g vs. 3395 g); and regarding yield in channel, the control treatment presented better outputs than the others (71,8 % vs 71,3 %). Examining other criteria, outputs favor chromium treatments: wings (172,9 g vs. 181,5 g), breasts (536,3 g vs. 545,1 g), and legs (669,1 g vs. 708,6 g). Therefore, it was determined that treatment 2 brings better economic results

Aportaciones al conocimiento de las comunidades de Pistacia Terenbinthus L. y de Acer Monspessulanum L. en el Sur de la Península Ibérica

Se aportan nuevos datos fitosociológicos sobre los terebintales-cornicabrales béticos, con la propuesta de una nueva asociación (Phillyreo latifoliae-Pistacietum terebinthi ass. nova) que representa a las formaciones de microfanerófitos mediterráneos perennifolios integrados en Quercetalia ilicis pero dominados por algunas especies caducifolias como Pistacia terebinthus. Se define también una nueva subasociación de los quejigares bético-torcalenses (Vinco difformis-Quercetum fagineae aceretosum monspessulani subass. nova) cuyo significado fitocenológico corresponde a un enriquecimiento en especies eurosiberianas y submediterráneas de Quercetalia pubescentis, fundamentalmente debido a un incremento en la altitud y a causa de las condiciones microclimáticas del biotopo en el que se asienta dicha comunidad.Contribution to the noules of the comunities of Pistacia terebinthus and Acer monspessulanum in Southern Iberian Peninsula. New phytosociological data about winter-deciduous pistachio tree forest (Phillyreo latifoliae-Pistacietum terebinthi ass. nova) endemic of the Betica province and Mediterranean region are presented. This new association is formed quantitatively by an evergreen forest; however there might predominate deciduous species such as Pistacia terebinthus. In addition, we propose a new subassociation of maple forest into the Torcalense phytogeographical subsector (Vinco difformis-Quercetum fagineae aceretosum monspessulani subass. nova). This subassociation develops on higher areas with north exposition. These conditions enable eurosiberian and submediterranean species, which belong to the phytosociological order of Quercetalia pubescentis

Las comunidades escionitrófilas de Alliaria petiolata (M. Bieb.) Cavara & Grande en el sur de la Península Ibérica

Las comunidades caracterizadas por Alliaria petiolata en el sur de la Península Ibérica corresponden a la asociación Myrrhoidi nodosae-Alliarietum petiolatae (clase Galio-Urticetea). Dicha asociación presenta su óptimo en la Sierra de Ayllón (Provincia Carpetano-Ibérico-Leonesa), e irradia hacia el suroeste por los sistemas béticos (provincia corológica Bética), cambiando su composición florística y empobreciéndose en esa dirección, siguiendo los distintos sectores fitogeográficos. Estos aspectos son reflejados fielmente por tres subasociaciones y una variante: subass. smyrnietosum perfoliati (subsectores Cazorlense y Alcaracense), subass. nepetosum granatensis (sectores Nevadense y Almijaro-Granatense) y subass. ranunculetosum blepharicarpi comb. nova (subsector Torcalense), que llega de modo finícola como variante supramediterránea con Sysimbrium crassifolium al extremo suroeste de las cordilleras (sector Rondeño). Esta distribución manifiesta una vía migratoria para taxones y sintaxones orófilos y mesófilos por las montañas béticas. Además, Alliaria petiolata, por su propia autoecología, su cortejo florístico y el hábitat que precisa, es un fiel bioindicador de bosques caducifolios, riparios y de abetos, que se pueden considerar hoy día muy singulares por su carácter relicto, submediterráneo o por habitar condiciones ecológicas especiales.Plant communities with Alliaria petiolata (M. Bieb.) Cavara & Grande in the South of the Iberian Peninsula. Plant communities characterized by Alliaria petiolata in the south of de Iberian Peninsula can be included in Myrrhoidi nodosae-Alliarietum petiolatae association (Galio-Urticetea class). This association is located in Ayllon mountains (Carpetano-Ibérico-Leonesa province) and distributed towards the southwest by the Betic mountain ranges (Betic chorological province) varying its floristic composition as the association reaches the different phytogeographical sectors. These aspects are clearly defined by three subassociations and one variant: subass. smyrnietosum perfoliati (Cazorlense and Alcaracense subsectors), subass. nepetosum granatensis (Nevadense y and Almijaro-Granatense sectors) and subass. ranunculetosum blepharicarpi comb. nova (Torcalense subsector) that reaches the southwest limit of Betic ranges as a supramediterranean variant with Sisymbrium crassifolium (Rondeño sector). This distribution may indicate a migratory route for orophyllous and mesophyllous taxa and syntaxa throughout the Betic Mountains. Moreover, Alliaria petiolata is an accurate bioindicator for the undergrowth of deciduous, riparian and mixed Abies pinsapo forests considered actually remarkable because of its relict character, sub-Mediterranean phytogeographical position, or special ecological requirements

Multipartite entanglement in fermionic systems via a geometric measure

We study multipartite entanglement in a system consisting of indistinguishable fermions. Specifically, we have proposed a geometric entanglement measure for N spin-1/2 fermions distributed over 2L modes (single particle states). The measure is defined on the 2L qubit space isomorphic to the Fock space for 2L single particle states. This entanglement measure is defined for a given partition of 2L modes containing m >= 2 subsets. Thus this measure applies to m <= 2L partite fermionic system where L is any finite number, giving the number of sites. The Hilbert spaces associated with these subsets may have different dimensions. Further, we have defined the local quantum operations with respect to a given partition of modes. This definition is generic and unifies different ways of dividing a fermionic system into subsystems. We have shown, using a representative case, that the geometric measure is invariant under local unitaries corresponding to a given partition. We explicitly demonstrate the use of the measure to calculate multipartite entanglement in some correlated electron systems. To the best of our knowledge, there is no usable entanglement measure of m > 3 partite fermionic systems in the literature, so that this is the first measure of multipartite entanglement for fermionic systems going beyond the bipartite and tripartite cases.Comment: 25 pages, 8 figure