Spin transport in dangling-bond wires on doped H-passivated Si(100)

New advances in single-atom manipulation are leading to the creation of atomic structures on H passivated Si surfaces with functionalities important for the development of atomic and molecular based technologies. We perform total-energy and electron-transport calculations to reveal the properties and understand the features of atomic wires crafted by H removal from the surface. The presence of dopants radically change the wire properties. Our calculations show that dopants have a tendency to approach the dangling-bond wires, and in these conditions, transport is enhanced and spin selective. These results have important implications in the development of atomic-scale spintronics showing that boron, and to a lesser extent phosphorous, convert the wires in high-quality spin filters.Comment: 11 pages, 4 figure

Laboratori remot de proteccions elèctriques

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Monetary policy and the output gap

Para una adecuada conducción de la política monetaria en una economía pequeña y abierta como la colombiana, debe tenerse en cuenta tanto el trilema de la política monetaria, como el ancla nominal de la economía. En este contexto, el papel del banco central es el de decidir cuál es el ancla nominal para la economía. Sin embargo, existe simultáneamente una estrecha relación entre la política monetaria y la brecha del producto. El objetivo de este estudio es ilustrar esta dinámica a través de un modelo de política monetaria. Los resultados muestran la relación dinámica entre el comportamiento de la tasa de interés como función de la inflación subyacente y la brecha del producto. Una de las principales características de la solución es que la restricción de no negatividad sobre la tasa de interés es obligatoria para bajos niveles de brecha del producto y bajas tasas de inflaciónTo develops an adequate an monetary policy, in a small open economy like the Colombian, must take in to account, the Trilema of monetary policy and the nominal anchor of the economy, in this context, the central bank role is that the decide which is the nominal anchor to the economy, however exist simultaneously a close relationship between the monetary policy and the gross domestic product gap, the goal of this study is to illustrate this dynamic thought of an monetary policy model, the results show that the behavior of an optimal interest rate like a function of the subjacent inflation and the gross domestic product gap, one of the principal characteristics of the solutions is that the restrictions of no negativity over the interest rate is necessary to lowers levels of gross domestic product gap and lowers rates of inflatio

Structural and magnetic properties of FeMnx_x (x=x=1...6) chains supported on Cu2_2N / Cu (100)

Heterogeneous atomic magnetic chains are built by atom manipulation on a Cu$_2$N/Cu (100) substrate. Their magnetic properties are studied and rationalized by a combined scanning tunneling microscopy (STM) and density functional theory (DFT) work completed by model Hamiltonian studies. The chains are built using Fe and Mn atoms ontop of the Cu atoms along the N rows of the Cu$_2$N surface. Here, we present results for FeMn$_x$ ($x$=1...6) chains emphasizing the evolution of the geometrical, electronic, and magnetic properties with chain size. By fitting our results to a Heisenberg Hamiltonian we have studied the exchange-coupling matrix elements $J$ for different chains. For the shorter chains, $x \leq 2$, we have included spin-orbit effects in the DFT calculations, extracting the magnetic anisotropy energy. Our results are also fitted to a simple anisotropic spin Hamiltonian and we have extracted values for the longitudinal-anisotropy $D$ and transversal-anisotropy $E$ constants. These parameters together with the values for $J$ allow us to compute the magnetic excitation energies of the system and to compare them with the experimental data.Comment: 10 pages 8 figure

Naturalness of MSSM dark matter

There exists a vast literature examining the electroweak (EW) fine-tuning problem in supersymmetric scenarios, but little concerned with the dark matter (DM) one, which should be combined with the former. In this paper, we study this problem in an, as much as possible, exhaustive and rigorous way. We have considered the MSSM framework, assuming that the LSP is the lightest neutralino, $\chi_1^0$, and exploring the various possibilities for the mass and composition of $\chi_1^0$, as well as different mechanisms for annihilation of the DM particles in the early Universe (well-tempered neutralinos, funnels and co-annihilation scenarios). We also present a discussion about the statistical meaning of the fine-tuning and how it should be computed for the DM abundance, and combined with the EW fine-tuning. The results are very robust and model-independent and favour some scenarios (like the h-funnel when $M_{\chi_1^0}$ is not too close to $m_h/2$) with respect to others (such as the pure wino case). These features should be taken into account when one explores "natural SUSY" scenarios and their possible signatures at the LHC and in DM detection experiments.Comment: 28 pages, 18 figures. References added, matches JHEP published versio

Diseño e implementación de un sistema de segmentación de los juegos de casinos de acuerdo con su nivel de actividad

El sector al cual apunta nuestro proyecto es el sector de la industria del Juego, específicamente en el sistema de las máquinas tragamonedas, las cuales bajo la perspectiva de un modelo de minería de datos permita a los administradores obtener conclusiones a fin de aplicarlas en su modelo de negocios. Específicamente tratamos el negocio de la empresa Interecuador S.A. dedicada al negocio de explotación de máquinas tragamonedas en calle, en locales y en salas de juego y casinos. El negocio posee diversos productos que pueden ser catalogados bajo dos grandes categorías: Mesas y máquinas. Dentro de mesas abarca todos los juegos de azar basados en cartas que tienen la intervención humana, este tipo de productos es exclusivo de casinos. Dentro de máquinas existen múltiples variedades de marcas, modelos y juegos los cuales se utilizan tanto en el negocio de calle, locales, casinos y salas de juego. Dadas las diversas características de los mismos es necesaria la implementación de un método que nos permita explorar los datos y encontrar la mejor combinación de características de determinada máquina de manera que su implementación en determinado local basado en la estadística me garantice la mejor producción de la misma

Fundamentos jurídicos para establecer la factibilidad de la aplicación de la terminación anticipada como incidente previo en la audiencia de control de acusación

Las reformas del derecho procesal penal latinoamericano se vincula con nuestro código procesal penal y los procesos especiales que acarrea consigo, en especial la terminación anticipada es uno de los exponentes de la justicia penal negociada logrando el consenso entre el fiscal y el imputado sobre la imputación, la pena y la reparación civil. En ese sentido, la presente investigación titulada “Fundamentos Jurídicos Para Establecer La Factibilidad De La Aplicación De La Terminación Anticipada Como Incidente Previo En La Audiencia De Control De Acusación” tiene como objetivo determinar cuáles son los fundamentos jurídicos que establecen la factible aplicación de la terminación anticipada como incidente previo en la audiencia de control de acusación. La investigación de acuerdo a la orientación es de tipo básica, de acuerdo a la técnica de contrastación es de tipo descriptiva, explicativa y propositiva. Con un diseño no experimental. En esta investigación se consideró como población a pronunciamientos, resoluciones, doctrina y legislación comparada, en ese sentido, la muestra que se utilizó en la presente investigación es de la cantidad de 3 pronunciamientos, siendo estos 2 acuerdos plenarios y 1 pleno jurisdiccional distrital, respecto a las resoluciones se utilizó la resolución nro. Cuatro del expediente 3356-2021-43, la resolución nro. Cinco del expediente 00079-2016-15 y la resolución nro. Tres del expediente 00167-2021-23 (Acta de audiencia), con la doctrina se utilizó a los juristas Giammpol Taboada Pilco, Benji Espinoza Ramos y Fredy Del Pino Huamán, y en la legislación comparada se utilizó la legislación de Colombia y de Chile. Cabe agregar que, respecto a las técnicas, tenemos las siguientes, técnica de la lectura utilizando el instrumento de la guía de observación y la técnica de recopilación documental mediante le instrumento de la guía de observación. Concerniente a los métodos lógicos se utilizó el método deductivo, respecto a los métodos jurídicos se utilizaron el método histórico y el método doctrinario. Como conclusión general, los fundamentos jurídicos que establecerán la factible aplicación de la terminación anticipada como incidente previo en la audiencia de control de acusación serían: la celeridad procesal y economía procesal, la vii aligeración de carga procesal, la ausencia de una acusación valida, evitar juicios innecesarios, el resarcimiento adecuado del actor civil y beneficio premial para el imputado.The reforms of latín american criminal procedure law are linked to our criminal procedure code and the special processes that it entails, especially the early termination is one of the exponents of the negotiated criminal justice achieving consensus between the prosecutor and the accused on the charge, the penalty and civil reparation. In this sense, the present research entitled “Legal Foundations To Establish The Feasibility Of The Application Of Early Termination As A Prior Incident In The Indictment Control Hearing” aims to determine which are the legal foundations that establish the feasibility of the application of early termination as a prior incident in the indictment control hearing. The research according to the orientation is of basic type, according to the contrast technique it is descriptive, explanatory and propositive. With a non- experimental design. In this research, the population was considered as pronouncements, resolutions, doctrine and comparative legislation, in that sense, the sample used in this research is the amount of 3 pronouncements, being these 2 plenary agreements and 1 district jurisdictional plenary, with respect to the resolutions, resolution no. Four of file 3356-2021-43, resolution no. Five of file 00079-2016-15 and resolution no. Three of file 00167-2021-23 (Minutes of hearing), with the doctrine the jurists Giammpol Taboada Pilco, Benji Espinoza Ramos and Fredy Del Pino Huamán were used, and in comparative legislation the legislation of Colombia and Chile was used. It should be added that, with respecto to the techniques, we have the following: reading techniques using the observation guide instrument and the documentary compilation technique using the observation guide instrumente. Regarding the logical methods, the deductive method was used; regarding the legal methods, the historical method and the doctrinal method were used. As a general conclusion, the legal grounds that will establish the feasible application of early termination as a prior incident in the indictment control hearing would be: procedural speed and procedural economy, lightening the procedural burden, the absence of a valid accusation, avoiding unnecessary trials, the adequate compesatin of the civil actor and the rewarding benefit for the accused.Tesi

Site- and orbital-dependent charge donation and spin manipulation in electron-doped metal phthalocyanines

Chemical doping offers promise as a means of tailoring the electrical characteristics of organic molecular compounds. However, unlike for inorganic semiconductors used in electronics applications, controlling the influence of dopants in molecular complexes is complicated by the presence of multiple doping sites, electron acceptor levels, and intramolecular correlation effects. Here we use scanning tunnelling microscopy to analyse the position of individual Li dopants within Cu- and Ni-phthalocyanine molecules in contact with a metal substrate, and probe the charge transfer process with unprecedented spatial resolution. We show that individual phthalocyanine molecules can host at least three distinct stable doping sites and up to six dopant atoms, and that the ligand and metal orbitals can be selectively charged by modifying the configuration of the Li complexes. Li manipulation reveals that charge transfer is determined solely by dopants embedded in the molecules, whereas the magnitude of the conductance gap is sensitive to the molecule-dopant separation. As a result of the strong spin-charge correlation in confined molecular orbitals, alkali atoms provide an effective way for tuning the molecular spin without resorting to magnetic dopants. © 2013 Macmillan Publishers Limited. All rights reserved.This work was supported by the European Research Council (StG 203239 NOMAD), Ministerio de Economía y Competitividad (MAT2010-15659), and Agència de Gestió d'Ajuts Universitaris i de Recerca (2009 SGR 695). A.M. acknlowledges the Spanish Ministerio de Ciencia e Innovación for a Ramon y Cajal Fellowship.Peer Reviewe