Interferometric modulation of quantum cascade interactions

We consider many-body quantum systems dissipatively coupled by a cascade network, i.e. a setup in which interactions are mediated by unidirectional environmental modes propagating through a linear optical interferometer. In particular we are interested in the possibility of inducing different effective interactions by properly engineering an external dissipative network of beam-splitters and phase-shifters. In this work we first derive the general structure of the master equation for a symmetric class of translation-invariant cascade networks. Then we show how, by tuning the parameters of the interferometer, one can exploit interference effects to tailor a large variety of many-body interactions.Comment: 12 pages, 10 figure

The X-ray emission of the Crab-like pulsar PSR J0537-6910

In this paper we present some preliminary result on the spectral and timing analysis of the X-ray pulsed emission from the 16 ms pulsar PSR J0537-6910 in the energy range 0.1--30 keV, based on archival BeppoSAX and RossiXTE observations. This pulsar, discovered by Marshall et al.(1998) in the LMC field with RXTE, is the fastest spinning pulsar associated with a supernova remnant. It is characterized by strong glitch activity with the highest rate of all known Crab-like system.Comment: 4 pages, 2 figures. Contribution to the proceedings of "The Restless High-Energy Universe", Amsterdam, May 5-8, 2003. Editors: E.P.J. van den Heuvel, J.J.M. in't Zand, R.A.M.J. Wijer

Interferometric Quantum Cascade Systems

In this work we consider quantum cascade networks in which quantum systems are connected through unidirectional channels that can mutually interact giving rise to interference effects. In particular we show how to compute master equations for cascade systems in an arbitrary interferometric configuration by means of a collisional model. We apply our general theory to two specific examples: the first consists in two systems arranged in a Mach-Zender-like configuration; the second is a three system network where it is possible to tune the effective chiral interactions between the nodes exploiting interference effects.Comment: 15 pages, 5 figure

The fair from Simoca : potentialities from development and impact urban

La presente Idea Fuerza de un Polo de Desarrollo Territorial se implementará en la Feria sabatina de Simoca, en donde se caracteriza como un espacio de comercialización de los productos típicos de la región. La idea principal se basara en fortalecer la inclusión social y el desarrollo rural de los pequeños productores de todo el departamento de Simoca, integrando las económicas regionales y locales apuntadas a la comercialización en la feria, generando ingresos adicionales a las familias. El objetivo de este trabajo es analizar la Feria de Simoca como actividad productiva convocante y oportunidad de crear un Polo de Desarrollo Territorial con diversas implicancias y con la participación de todos los actores involucrados en forma directa e indirecta en la feria. Autores como Sevilla Guzman y Alemany plantean respecto al desarrollo territorial sustentable, que puede entenderse al mismo como una construcción social, compleja, dinámica y multidimensional (ecológica, social, cultural, ética, política y económica), donde la extensión rural tiene especificidades importantes que contribuyen a esta construcción por su articulación entre los actores involucrados en la problemática del desarrollo local, la articulación entre la producción, la distribución y el consumo, en el fortalecimiento de los procesos locales, con su dotación de recursos naturales, su identidad, su conocimiento y su organización, en la vinculación con lo global, sus desarrollos teóricos y su praxis de diferentes disciplinas del conocimiento científico, la transdisciplinaridad y su acción de reflexión-acción de los seres humanos sobre su realidad para su transformación. A nivel urbano determinar el impacto que produce en la ciudad detectando falencias posibles de mejorar. La metodología consistió en revisión bibliográfica y documental, lectura, análisis y clasificación de toda la información recogida. Diseño del instrumento de acopio de la información y planificación de un cronograma de visitas a actores sociales, definidos como informantes calificados o claves por su condición de liderazgo en la zona. Se llevaron a cabo entrevistas y encuestas. Como resultado alcanzado fue estudiar de esta manera el patrimonio inmaterial analizando el impacto cultural en el territorio, sus potencialidades de desarrollo socio productivo y el patrimonio material en su manifestación contundente en la ciudad.Fil: Cusumano, Cosme Orlando. Instituto Nacional de Tecnología Agropecuaria (Argentina)Fil: Cusumano, Julio Ricardo. Instituto Nacional de Tecnología Agropecuaria (Argentina

The optical to gamma-ray emission of the Crab pulsar: a multicomponent model

We present a multicomponent model to explain the features of the pulsed emission and spectrum of the Crab Pulsar, on the basis of X and gamma-ray observations obtained with BeppoSAX, INTEGRAL and CGRO. This model explains the evolution of the pulse shape and of the phase-resolved spectra, ranging from the optical/UV to the GeV energy band, on the assumption that the observed emission is due to more components. The first component, C_O, is assumed to have the pulsed double-peaked profile observed at the optical frequencies, while the second component, C_X, is dominant in the interpeak and second peak phase regions. The spectra of these components are modelled with log-parabolic laws and their spectral energy distributions have peak energies at 12.2 and 178 keV, respectively. To explain the properties of the pulsed emission in the MeV-GeV band, we introduce two more components, C_Ogamma and C_Xgamma, with phase distributions similar to those of C_O and C_X and log-parabolic spectra with the same curvature but peak energies at about 300 MeV and 2 GeV. This multicomponent model is able to reproduce both the broadband phase-resolved spectral behaviour and the changes of the pulse shape with energy. We also propose some possible physical interpretations in which C_O and C_X are emitted by secondary pairs via a synchrotron mechanism while C_Ogamma and C_Xgamma can originate either from Compton scattered or primary curvature photons.Comment: 14 pages, 16 figures; accepted by Astronomy and Astrophysic

Donor/Acceptor Heterojunction Organic Solar Cells

The operation and the design of organic solar cells with donor/acceptor heterojunction structure and exciton blocking layer is outlined and results of their initial development and assessment are reported. Under halogen lamp illumination with 100 mW/cm2 incident optical power density, the devices exhibits an open circuit voltage VOC = 0.45 V, a short circuit current density JSC between 2 and 2.5 mA/cm2 with a fill factor FF ≈ 50%, an external quantum efficiency (electrons/s over incident photons/s) EQE ≈ 5% and a power conversion efficiency of about 0.5%. Measurements of the photoelectrical characteristics with time are also reported, confirming that non encapsulated organic solar cells have limited stability in ambient atmosphere