La competencia judicial en los procesos de amparo por acceso a información. Referida a políticas públicas de infancia y adolescencia

El presente trabajo aborda la temática de la competencia judicial en los procesos promovidos ante la negativa de la Administración de proporcionar información que es indispensable para comprobar el efectivo goce de derechos de la infancia y la adolescencia; verificar la forma en la cual se le da cumplimiento a principios recogidos en la normativa nacional o internacional que le reconoce los derechos humanos de la infancia y la adolescencia, o cuando dicha información es necesaria para realizar una tarea de contralor de las políticas públicas relativas a esos derechos

A monolayer transition-metal dichalcogenide as a topological excitonic insulator

Monolayer transition-metal dichalcogenides in the T\u2032 phase could enable the realization of the quantum spin Hall effect1 at room temperature, because they exhibit a prominent spin\u2013orbit gap between inverted bands in the bulk2,3. Here we show that the binding energy of electron\u2013hole pairs excited through this gap is larger than the gap itself in the paradigmatic case of monolayer T\u2032 MoS2, which we investigate from first principles using many-body perturbation theory4. This paradoxical result hints at the instability of the T\u2032 phase in the presence of spontaneous generation of excitons, and we predict that it will give rise to a reconstructed \u2018excitonic insulator\u2019 ground state5\u20137. Importantly, we show that in this monolayer system, topological and excitonic order cooperatively enhance the bulk gap by breaking the crystal inversion symmetry, in contrast to the case of bilayers8\u201316 where the frustration between the two orders is relieved by breaking time reversal symmetry13,15,16. The excitonic topological insulator is distinct from the bare topological phase because it lifts the band spin degeneracy, which results in circular dichroism. A moderate biaxial strain applied to the system leads to two additional excitonic phases, different in their topological character but both ferroelectric17,18 as an effect of electron\u2013electron interaction

First-Principles Calculations of Exciton Radiative Lifetimes in Monolayer Graphitic Carbon Nitride Nanosheets: Implications for Photocatalysis

In this work, we report on the exciton radiative lifetimes of graphitic carbon nitride monolayers in the triazine-based (gC3N4-t) and heptazine-based (gC3N4-h) forms, as obtained by means of ground-state plus excited-state ab initio calculations. By analyzing the exciton fine structure, we highlight the presence of dark states and show that the photogenerated electron-hole (e-h) pairs in gC3N4-h are remarkably long-lived, with an effective radiative lifetime of 260 ns. This fosters the employment of gC3N4-h in photocatalysis and makes it attractive for the emerging field of exciton devices. Although very long intrinsic radiative lifetimes are an important prerequisite for several applications, pristine carbon nitride nanosheets show very low quantum photoconversion efficiency, mainly due to the lack of an efficient e-h separation mechanism. We then focus on a vertical heterostructure made of gC3N4-t and gC3N4-h layers, which shows a type-II band alignment and looks promising for achieving net charge separation

Test of long-range exchange-correlation kernels of time-dependent density functional theory at surfaces: Application to Si(111)2×1

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Spinorial formulation of the GW-BSE equations and spin properties of excitons in two-dimensional transition metal dichalcogenides

In many paradigmatic materials, such as transition metal dichalcogenides, the role played by the spin degrees of freedom is as important as the one played by the electron-electron interaction. Thus an accurate treatment of the two effects and of their interaction is necessary for an accurate and predictive study of the optical and electronic properties of these materials. Despite the fact that the GW-BSE approach correctly accounts for electronic correlations, the spin-orbit coupling effect is often neglected or treated perturbatively. Recently, spinorial formulations of GW-BSE have become available in different flavors in material-science codes. However, an accurate validation and comparison of different approaches is still missing. In this work, we go through the derivation of the noncollinear GW-BSE approach. The scheme is applied to transition metal dichalcogenides comparing the perturbative and full spinorial approaches. Our calculations reveal that dark-bright exciton splittings are generally improved when the spin-orbit coupling is included nonperturbatively. The exchange-driven intravalley mixing between the A and B excitons is found to play a role for Mo-based systems, being especially strong in the case of MoSe 2 . We finally compute the excitonic spin and use it to sharply analyze the spinorial properties of transition metal dichalcogenide excitonic states

Segregation, quantum confinement effect and band offset for [110] SiGe NWs

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Ab initio optoelectronic properties of SiGe nanowires: Role of many-body effects

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Ab initio pseudopotential calculation of the equilibrium structure of tin monoxide

We present an ab initio pseudopotential calculation of the structural properties of stannous oxide SnO. We discuss the delicate balance of different contributions to the cohesion of this material, and compare the monoxide to the dioxide SnO2. We point out how different choices concerning the pseudopotential of tin may dramatically influence the resulting equilibrium structure of SnO, and show that the physically most appropriate choice leads to excellent agreement with experiment

Study of a Nonlocal Density scheme for electronic--structure calculations

An exchange-correlation energy functional beyond the local density approximation, based on the exchange-correlation kernel of the homogeneous electron gas and originally introduced by Kohn and Sham, is considered for electronic structure calculations of semiconductors and atoms. Calculations are carried out for diamond, silicon, silicon carbide and gallium arsenide. The lattice constants and gaps show a small improvement with respect to the LDA results. However, the corresponding corrections to the total energy of the isolated atoms are not large enough to yield a substantial improvement for the cohesive energy of solids, which remains hence overestimated as in the LDA.Comment: 4 postscript figure

Duration of untreated illness predicts 3-year outcome in patients with obsessive-compulsive disorder: A real-world, naturalistic, follow-up study

Duration of untreated illness (DUI) is a predictor of outcome in psychotic and affective disorders. The few available data on the effect of DUI in obsessive-compulsive disorder (OCD) suggest an association between longer DUI and poorer response to treatments. This is a real-world, naturalistic, follow-up study evaluating the impact of DUI on long-term clinical outcomes. The sample consists of 83 outpatients with OCD with a mean DUI of 7.3 (5.8) years. Patients with symmetry/ordering cluster symptoms were younger at onset of the disease (20.4 ± 7.9 vs. 27.8 ± 10.6; p<.05, d = 0.79), had a longer duration of the illness (10.1 ± 4.6 vs. 6.8 ± 4.6, p<.05; d = 0.53) and a longer DUI (7.9 ± 6.5 vs. 5.4 ± 3.6, p<.05, d = 0.49) compared to patients not presenting with those symptoms. Fifty-nine patients completed the follow-up, and 33.9% (N = 20) met the criteria for partial remission, scoring <15 at the Y-BOCS for at least eight weeks. Patients in partial remission for more than 40% of the follow-up were defined as “good outcome” and they had a significantly shorter DUI compared to patients with “poor outcome”. Access to adequate treatments is highly delayed in patients with OCD. DUI is strongly associated with poor treatment outcomes. Therefore, strategies to ensure an early diagnosis and treatment are needed