Matrices of fidelities for ensembles of quantum states and the Holevo quantity

The entropy of the Gram matrix of a joint purification of an ensemble of K mixed states yields an upper bound for the Holevo information Chi of the ensemble. In this work we combine geometrical and probabilistic aspects of the ensemble in order to obtain useful bounds for Chi. This is done by constructing various correlation matrices involving fidelities between every pair of states from the ensemble. For K=3 quantum states we design a matrix of root fidelities that is positive and the entropy of which is conjectured to upper bound Chi. Slightly weaker bounds are established for arbitrary ensembles. Finally, we investigate correlation matrices involving multi-state fidelities in relation to the Holevo quantity.Comment: 24 pages, 3 figure

Resource-Efficient Chemistry on Quantum Computers with the Variational Quantum Eigensolver and the Double Unitary Coupled-Cluster Approach.

Applications of quantum simulation algorithms to obtain electronic energies of molecules on noisy intermediate-scale quantum (NISQ) devices require careful consideration of resources describing the complex electron correlation effects. In modeling second-quantized problems, the biggest challenge confronted is that the number of qubits scales linearly with the size of the molecular basis. This poses a significant limitation on the size of the basis sets and the number of correlated electrons included in quantum simulations of chemical processes. To address this issue and enable more realistic simulations on NISQ computers, we employ the double unitary coupled-cluster (DUCC) method to effectively downfold correlation effects into the reduced-size orbital space, commonly referred to as the active space. Using downfolding techniques, we demonstrate that properly constructed effective Hamiltonians can capture the effect of the whole orbital space in small-size active spaces. Combining the downfolding preprocessing technique with the variational quantum eigensolver, we solve for the ground-state energy of H2, Li2, and BeH2 in the cc-pVTZ basis using the DUCC-reduced active spaces. We compare these results to full configuration-interaction and high-level coupled-cluster reference calculations

Truce in the Salmon War: Alternatives for the Pacific Salmon Treaty

The 1985 Pacific Salmon Treaty was heralded as an end to the ongoing international dispute between the United States and Canada over Pacific salmon fishing rights. The Treaty, however, failed to define adequately the principles and processes for allocating salmon harvests between the two countries. The parties to the Treaty have been unable to reach consensus on annual salmon harvests since 1992, fueling a growing conflict which has threatened to spill over to issues beyond the fishery dispute. This Article examines the historical context of the salmon war, highlighting changes in international law and domestic politics that affected the formation of the Treaty. The Pacific Salmon Treaty established a framework for the parties to cooperate in the management of salmon stocks, but did not define several key principles and created a cumbersome voting mechanism. These deficiencies have resulted in annual negotiations that are fraught with conflict, leading to a breakdown in the Treaty process. This Article analyzes several alternatives for solving this current crisis. The parties could submit the annual allocation decisions to an international arbitration board that would have the power to bind both sides. Each country could agree to compensate the other country monetarily for interceptions of the other\u27s salmon stocks. The Treaty could also be revised to provide for a default allocation scheme if the parties fail to reach agreement on annual fishery regulations. Finally, the United States and Canada could create an international market of individual salmon quotas. As this Article was being revised for publication, the United States and Canada entered into an historic agreement designed to end the Pacific salmon war. The Epilogue at Part VI of this Article discusses the new agreement and its future implications for Pacific salmon

Local indistinguishability: more nonlocality with less entanglement

We provide a first operational method for checking indistinguishability of orthogonal states by local operations and classical communication (LOCC). This method originates from the one introduced by Ghosh et al. (Phys. Rev. Lett. 87, 5807 (2001) (quant-ph/0106148)), though we deal with pure states. We apply our method to show that an arbitrary complete multipartite orthogonal basis is indistinguishable by LOCC, if it contains at least one entangled state. We also show that probabilistic local distinguishing is possible for full basis if and only if all vectors are product. We employ our method to prove local indistinguishability in an example with sets of pure states of 3X3, which shows that one can have ``more nonlocality with less entanglement'', where ``more nonlocality'' is in the sense of ``increased local indistinguishability of orthogonal states''. This example also provides, to our knowledge, the only known example where d orthogonal states in dXd are locally indistinguishable.Comment: 4 pages, no figures, RevTeX4, partially supersedes quant-ph/0204116, to appear in Phys. Rev. Let

Band Offsets at the Interface Between Crystalline and Amorphous Silicon from First Principles

The band offsets between crystalline and hydrogenated amorphous silicon (a−Si∶H) are key parameters governing the charge transport in modern silicon heterojunction solar cells. They are an important input for macroscopic simulators that are used to further optimize the solar cell. Past experimental studies, using x-ray photoelectron spectroscopy (XPS) and capacitance-voltage measurements, have yielded conflicting results on the band offset. Here, we present a computational study on the band offsets. It is based on atomistic models and density-functional theory (DFT). The amorphous part of the interface is obtained by relatively long DFT first-principles molecular-dynamics runs at an elevated temperature on 30 statistically independent samples. In order to obtain a realistic conduction-band position the electronic structure of the interface is calculated with a hybrid functional. We find a slight asymmetry in the band offsets, where the offset in the valence band (0.29 eV) is larger than in the conduction band (0.17 eV). Our results are in agreement with the latest XPS measurements that report a valence-band offset of 0.3 eV [M. Liebhaber et al., Appl. Phys. Lett. 106, 031601 (2015)]

Rehabilitación neuropsicológica en personas con síndrome de Prader-Willi

El síndrome de Prader-Willi (SPW) es un trastorno complejo del neurodesarrollo causado por anomalías genéticas y que presenta un fenotipo neuroconductual característico. El objetivo de este trabajo fue analizar las intervenciones de rehabilitación neuropsicológica en SPW, por lo que se realizó una búsqueda sistemática, incluyéndose un total de 14 artículos con intervenciones en características fenotípicas conductuales, cognitivas o familiares. Los estudios fueron analizados según el enfoque de la intervención, modelos, procedimientos específicos y resultados. La mayor parte de los estudios utilizaron un modelo de compensación y casi todos aplicaron técnicas de modificación conductual. Los resultados sugieren que las técnicas que utilizan un reforzamiento diferencial, que incluyen una mayor participación de la persona con SPW y sus familiares en el proceso de intervención, son más exitosas

Neuropsychological rehabilitation in people with Prader-Willi syndrome

Prader-Willi Syndrome (PWS) is a complex neurodevelopmental disorder caused by genetic anomalies that presents itself with a characteristic neurobehavioral phenotype. The aim of this project was to analyze interventions of neuropsychological rehabilitation that exist in PWS and to achieve it, a systematic search was done, resulting in a total of 14 articles with interventions for behavioral, cognitive and familial phenotypical characteristics. The studies were analyzed according to the focus of the intervention, models, specific procedures and results. Most studies used a compensation model and almost all applied behavioral modification techniques. The results suggest that techniques that use differential reinforcement and a more active involvement of the person with PWS and their family during intervention, are more successful

O procurador do trabalho e o SUS – Ministério Público do Trabalho e política nacional de saúde do trabalhador: interface entre o papel de promotor social e a busca pela intersetorialidade.

Introduction: The Public Labor Ministry (MPT), a specialized branch of the Public Ministry of the Union (MPU), is one of the fundamental actors in the promotion and protection of workers, and despite it is not expressly mentioned in the National Health and Worker Safety Policy, it has valuable potential for dialogue and promotion of intersectoriality for the construction and implementation of public policies, that provide action in favor of Decent Work, as recommended by the ILO. Objective: To emphasize the role of the MPT as a social promoter of public policies related to health and safety in the work area, specifically with regard to national policies, based on intersectoral practices. Methodology: It is a study of bibliographical and documentary research between 2010 and 2014. The bibliographic search was achieved based on the intersectoriality theme in Health and Safety at Work (HSW) policies in national journals available at the Scielo database and the documentary research was carried out in ministerial documents and official publications of the MPT, both in the same time cut. Results: From the parameters defined in the methodology, 37 articles were identified and analyzed, of which 16 were studies of SCIELO databases. Another 17 were published in official publications of the MPT, of which 7 were studies and 10 were procedural documents, mainly initial petitions for Public Civil Actions (ACPs). Among the 16 studies with intersectoral practices, there was reference to the articulation with MPT in 7 articles, which represents 43.75% of the cases of intersectoral practices in Worker's Health referenced in the databases used in the research. Conclusions: We conclude that the possibilities and potential of intersectoral articulation are broad. Even in the cases of intersectorial actions in which the participation of the MPT was not identified, we showed the potentials of action in each case, whose future prospects imply possibilities of interaction with the social actors of the SUS and others involved with the theme. The studies and speeches show that, even within the SUS, the construction of intersectoral actions is still a challenge, and articulation with the MPT is therefore a major challenge in the effective implementation of the National Policy Occupational Health and Safety. However, the combination of efforts, articulated among all social actors, may be able to modify the scenario that places Brazil in the first rankings of sickness and accidents at the expense of work, against the global picture.Dissertação (Mestrado)Introdução: O Ministério Público do Trabalho (MPT), ramo especializado do Ministério Público da União (MPU), é um dos atores fundamentais nas ações de promoção e proteção do trabalhador e, a despeito de não ter sido expressamente citado na Política Nacional de Saúde e Segurança do Trabalhador, possui valioso potencial de interlocução e de promoção da intersetorialidade para construção e implementação de políticas públicas que proporcionem atuação em prol do trabalho decente, conforme preconizado pela Organização Internacional do Trabalho (OIT). Objetivo: Visibilizar o papel do MPT enquanto promotor social de políticas públicas relacionadas à saúde e à segurança no âmbito do trabalho, especificamente no que diz respeito às políticas nacionais, por meio de práticas intersetoriais. Metodologia: Tratou-se de um estudo de caráter bibliográfico e de pesquisa documental compreendida entre 2010 a 2014. A busca bibliográfica foi feita com base na temática da intersetorialidade nas políticas de saúde e segurança do trabalho (SST) em periódicos nacionais disponibilizados pela biblioteca eletrônica Scielo, e a pesquisa documental foi realizada em documentos ministeriais e publicações oficiais do MPT sobre SST, ambas no mesmo recorte temporal. Resultados: Com base nos parâmetros definidos na metodologia, foram identificados e analisados 33 artigos, sendo 16 estudos coletados na base de dados da Scielo e outros 17 em publicações oficiais do MPT, dentre estes 7 estudos e 10 peças processuais, cuja maioria consiste em petições iniciais de Ações Civis Públicas (ACPs). Dentre os 16 estudos com práticas intersetoriais, houve referência a uma articulação com o MPT em 7 artigos, o que representa 43,75% dos casos de práticas intersetoriais em Saúde do Trabalhador referenciados nas bases de dados utilizadas na pesquisa. Conclusões: Concluímos que as possibilidades e potencialidades de articulação intersetoriais são amplas. Mesmo nos casos de ações intersetoriais em que não foi identificada a participação do MPT, evidenciamos os potenciais de atuação em cada caso, cuja prospecção futura enseja possibilidades de interação com os atores sociais do Sistema Único de Saúde (SUS) e demais envolvidos com a temática. Os estudos e as falas revelam que, na prática, mesmo dentro do SUS, a construção de ações intersetoriais ainda é trabalhosa, e a articulação com o MPT torna-se, portanto, um desafio maior no tocante à implementação efetiva da Política Nacional de Saúde e Segurança do Trabalhador. Porém, a junção de esforços articulados entre todos os atores sociais pode modificar o cenário que coloca o Brasil nas primeiras posições em rankings de adoecimento e acidentes no trabalho no quadro mundial