Hybrid photonic entanglement: Realization, characterization and applications

We show that the quantum disentanglement eraser implemented on a two-photon system from parametric down-conversion is a general method to create hybrid photonic entanglement, namely the entanglement between different degrees of freedom of the photon pair. To demonstrate this, we generate and characterize a source with tunable degree of hybrid entanglement between two qubits, one encoded in the transverse momentum and position of a photon, and the other in the polarization of its partner. In addition, we show that a simple extension of our setup enables the generation of two-photon qubit-qudit hybrid entangled states. Finally, we discuss the advantages that this type of entanglement can bring for an optical quantum network.Comment: Published versio

Quantum localized states in photonic flat-band lattices

The localization of light in flat-band lattices has been recently proposed and experimentally demonstrated in several configurations, assuming a classical description of light. Here, we study the problem of light localization in the quantum regime. We focus on quasi one-dimensional and two-dimensional lattices which exhibit a perfect flat-band inside their linear spectrum. Localized quantum states are constructed as eigenstates of the interaction Hamiltonian with a vanishing eigenvalue and a well defined total photon number. These are superpositions of Fock states with probability amplitudes given by positive as well as negative square roots of multinomial coefficients. The classical picture can be recovered by considering poissonian superpositions of localized quantum states with different total photon number. We also study the separability properties of flat band quantum states and apply them to the transmission of information via multi-core fibers, where these states allow for the total passive suppression of photon crosstalk and exhibit robustness against photon losses. At the end, we propose a novel on-chip setup for the experimental preparation of localized quantum states of light for any number of photons.Comment: 12 pages, 5 figure

Políticas de saúde mental e direitos humanos

Na primeira unidade, apresenta a Reforma Psiquiátrica em suas quatro fases: crítica ao asilo mercantilizado; tratamento ambulatorial e mudança na legislação; construção da política nacional de saúde mental; e implantação de serviços em redes de atenção, mostrando as premissas, os pressupostos éticos e as diretrizes gerais do movimento, assim como as principais transformações dele originadas. Na segunda unidade aborda as questões ligadas aos Direitos Humanos, as rupturas e os esforços de continuidade na construção do conceito de dignidade humana, associada à igualdade universal e à solidariedade, sua relação com a realidade dos serviços de saúde mental suas demandas e necessidade de ultrapassar fronteiras, do enquadramento sanitário e jurídico do uso de drogas, dos desafios da atenção em saúde a novos públicos, das discussões envolvendo internação voluntária e compulsória e respeito à dignidade humana do diferente. São apresentadas, também, leituras complementares e referências.1.0Ministério da Saúd

Practical computational advantage from the quantum switch on a generalized family of promise problems

The quantum switch is a quantum computational primitive that provides computational advantage by applying operations in a superposition of orders. In particular, it can reduce the number of gate queries required for solving promise problems where the goal is to discriminate between a set of properties of a given set of unitary gates. In this work, we use Complex Hadamard matrices to introduce more general promise problems, which reduce to the known Fourier and Hadamard promise problems as limiting cases. Our generalization loosens the restrictions on the size of the matrices, number of gates and dimension of the quantum systems, providing more parameters to explore. In addition, it leads to the conclusion that a continuous variable system is necessary to implement the most general promise problem. In the finite dimensional case, the family of matrices is restricted to the so-called Butson-Hadamard type, and the complexity of the matrix enters as a constraint. We introduce the ``query per gate'' parameter and use it to prove that the quantum switch provides computational advantage for both the continuous and discrete cases. Our results should inspire implementations of promise problems using the quantum switch where parameters and therefore experimental setups can be chosen much more freely.Comment: 14 pages, 5 figures; more detailed Sections 4 and 5, added new references for section 5, other minor change

Efficient bipartite quantum state purification in arbitrary dimensional Hilbert spaces

A new purification scheme is proposed which applies to arbitrary dimensional bipartite quantum systems. It is based on the repeated application of a special class of nonlinear quantum maps and a single, local unitary operation. This special class of nonlinear quantum maps is generated in a natural way by a hermitian generalized XOR-gate. The proposed purification scheme offers two major advantages, namely it does not require local depolarization operations at each step of the purification procedure and it purifies more efficiently than other know purification schemes.Comment: This manuscript is based on results of our previous manuscript 'Generalized quantum XOR-gate for quantum teleportation and state purification in arbitrary dimensional Hilbert spaces

Las 5S para Incrementar la Productividad del Área de Mantenimiento de una Empresa de Transporte

La presente investigación respondió al siguiente problema general: ¿En qué medida la aplicación de la metodología 5S's incrementara la productividad en el área de mantenimiento de una Empresa de Transportes?, y el objetivo general fue determinar en qué medida la aplicación de la metodología 5S's incrementa la productividad en el área de mantenimiento de una Empresa de Transportes y la hipótesis general que se verificó es: La aplicación de la metodología 5S permitió incrementar la productividad en el área de mantenimiento de una empresa de Transportes. Siendo directa y significativa. El método de investigación fue el científico, el tipo de investigación fue aplicada, de nivel explicativo y de diseño no experimental. La población estuvo por 22 actividades del área de mantenimiento, no se utilizó la técnica de muestreo se trabajó con el total de la población, es decir se utilizó el fenómeno del censo. La conclusión a la que se llegó en la investigación fue que la aplicación de la metodología 5S's incrementa significativamente la productividad en el área de mantenimiento de una empresa de transporte en un 1.74%, reduciendo espacios perdidos y tiempo de ciclo.Tesi

Covid-19 in Peru: From supervised walks for children to the first case of Kawasaki-like syndrome

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