A non-Markovian optical signature for detecting entanglement in coupled excitonic qubits

We identify an optical signature for detecting entanglement in experimental nanostructure systems comprising coupled excitonic qubits. This signature owes its strength to non-Markovian dynamical effects in the second-order temporal coherence function of the emitted radiation. We calculate autocorrelation and cross-correlation functions for both selective and collective light excitation, and prove that the coherence properties of the emitted light do indeed carry information about the entanglement of the initial multi-qubit state. We also show that this signature can survive in the presence of a noisy environment.Comment: 4 pages, 4 color figures. Minor changes. Accepted version to be published in Europhysics Letter

Ultrafast optical signature of quantum superpositions in a nanostructure

We propose an unambiguous signature for detecting quantum superposition states in a nanostructure, based on current ultrafast spectroscopy techniques. The reliable generation of such superposition states via Hadamard-like quantum gates is crucial for implementing solid-state based quantum information schemes. The signature originates from a remarkably strong photon antibunching effect which is enhanced by non-Markovian dynamics.Comment: 4 pages, 2 figures. Published in Phys. Rev. B (Rapid Communications

Nonequilibrium dynamics of polariton entanglement in a cluster of coupled traps

We study in detail the generation and relaxation of quantum coherences (entanglement) in a system of coupled polariton traps. By exploiting a Lie algebraic based super-operator technique we provide an analytical exact solution for the Markovian dissipative dynamics (Master equation) of such system which is valid for arbitrary cluster size, polariton-polariton interaction strength, temperature and initial state. Based on the exact solution of the Master equation at T=0K, we discuss how dissipation affects the quantum entanglement dynamics of coupled polariton systems.Comment: 5 pages, 2 figures, SLAFES XIX contribution pape

La sucesión silúrica en tierras de Aliste y Carbajales (Zamora)

[Resumen] Se describe la sucesión silúrico-devónica que 'aparece al NW de la ciudad de Zamora, dentro de una sinforma de dirección NW-SE, que se extiende desde la frontera portuguesa hasta desaparecer bajo los depósitos terciarios de la meseta. La sucesión está datada mediante Conodontos y Graptolites, siendo muy completa, ya que abarca al menos desde el Llandovery 'inferior al Emsiense. La sucesión es ,en gran parte turbidítica y presenta un vulcanismo asociado[Abstract] The siluro-,devonian sequence North of Zamora crops out in the eore of a synformal structure up to the portuguese border, being covered by Cenozoic deposits to the East. The age of this sequence is established based on conodont and 'graptolite localities and ranges from lower Llandovery to Emsian. The materials arc mainly turbiditic land show important volcanic contribution

The spectroscopic orbits and the geometrical configuration of the symbiotic binary AR Pavonis

We analyze optical and near infrared spectra of intermediate and high resolution of the eclipsing symbiotic system AR Pavonis. We have obtained the radial velocity curves for the red and the hot component from the M-giant absorption lines and from the wings of Halpha, H and He II4686 emission profiles, respectively. From the orbital elements we have derived the masses, Mgiant=2.5 and Mhot =1.0 solar masses, for the red giant and the hot component, respectively. We also present and discuss radial velocity patterns in the blue cF absorption spectrum as well as various emission lines. In particular, we confirm that the blue absorption lines are associated with the hot component. The radial velocity curve of the blue absorption system, however, does not track the hot companion's orbital motion in a straightforward way, and its departures from an expected circular orbit are particularly strong when the hot component is active. We suggest that the cF-type absorption system is formed in material streaming from the giant presumably in a region where the stream encounters an accretion disk or an extended envelope around the hot component. The broad emission wings originate from the inner accretion disk or the envelope around the hot star.We also suggest that the central absorption in H profiles is formed in a neutral portion of the cool giant's wind which is strongly concentrated towards the orbital plane. The nebula in AR Pav seems to be bounded by significant amount of neutral material in the orbital plane. The forbidden emission lines are probably formed in low density ionized regions extended in polar directions and/or the wind-wind interaction zone.Comment: 12 pages, 5 figures, accepted by A&

Condiciones y Medio Ambiente de Trabajo … ¿qué se hace en la Universidad?

Las Condiciones y Medio Ambiente de Trabajo (CyMAT) abarcan la totalidad de los factores que pueden afectar al trabajador desde una visión integradora de sus necesidades económicas, técnicas y organizacionales, y consideran además la relación de las mismas con el medio socioeconómico, político, físico, sanitario y cultural que lo rodea. Esta mirada conjunta de los factores que pueden afectar al trabajador, sus necesidades y la relación de estas últimas con el medio, permite trasladar situaciones laborales al entorno familiar y social del trabajador, afectándolo tanto fuera como dentro del lugar donde realiza sus tareas. El marco legal está dado por la Ley Nº19.587 de Higiene y Seguridad con su Decreto Reglamentario Nº 351/79, y la Ley Nº24.557 de Riesgos del Trabajo de 1996. De acuerdo con estas normas, las universidades deben prever condiciones de seguridad para su personal, sus instalaciones y su equipamiento, elaborar manuales de procedimientos, programas de capacitación y planes de evacuación, y realizar registros de accidentes y de enfermedades laborales. El objetivo de este trabajo es concientizar a la comunidad universitaria de la importancia de este tema, normalmente percibido como secundario frente a cuestiones académicas, presupuestarias, políticas y de otros órdenes. Para ello se propone inspeccionar qué hacen las Universidades Nacionales respecto a esta problemática, revisando las páginas institucionales, los estándares para la acreditación de las carreras y los informes de evaluación disponibles en Internet