Nonclassical Radiation from Thermal Cavities in the Ultrastrong Coupling Regime

Thermal or chaotic light sources emit radiation characterized by a slightly enhanced probability of emitting photons in bunches, described by a zero-delay second-order correlation function $g^{(2)}(0) = 2$. Here we explore photon-coincidence counting statistics of thermal cavities in the ultrastrong coupling regime, where the atom-cavity coupling rate becomes comparable to the cavity resonance frequency. We find that, depending on the system temperature and coupling rate, thermal photons escaping the cavity can display very different statistical behaviors, characterised by second-order correlation functions approaching zero or greatly exceeding two.Comment: results on frequency resolved photon correlations added, to appear in Phys. Rev. Let

La mirada latina sobre la psicología positiva

El siguiente trabajo intenta mostrar el avance que presenta Latinoamérica en cuanto al estudio y aplicación de temáticas relacionadas con la Psicología Positiva (PP). Por un lado, se pretendió describir cómo ha surgido el interés en PP en algunos países de Latinoamérica como Argentina, Perú, México, entre otros. Por otro lado, se analizaron los resultados de un rastrillaje realizado en el cual verifica el cúmulo de trabajos y pruebas psicológicas desarrolladas en la región, principalmente teniendo en cuenta los pilares de la PP propuestos por Seligman (2002, 2009): las emociones positivas, los rasgos positivos, las instituciones positivas y los vínculos positivos (la vida social). México, Chile, Brasil y Argentina, parecen ser los países con mayor productividad. Las temáticas frecuentemente estudiadas están en relación con el bienestar psicológico, las relaciones interpersonales y las intervenciones psicoterapéuticas. Palabras clave: Psicología positiva, pilares, evaluación, Latinoamérica.The present article aims to describe the progress of the study and application of Positive Psychology (PP) in Latin America. On one hand, it is described how the interest in PP has emerged in some Latin American countries such as Argentina, Peru and Mexico, among others. On the other hand, results of a literature review which explore the development of psychological assessments in the region are presented according to PP pillars proposed by Seligman (2002, 2009): positive emotions, positive traits, positive institutions and positive relationships (social life). Mexico, Chile, Brazil and Argentina appeared to be the countries with the highest levels of scientific production related to PP and the topics most frequently studied are psychological well-being, interpersonal relationships and psychotherapeutic interventions.Fil: Castro Solano, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Palermo; ArgentinaFil: Lupano Perugini, Maria Laura. Universidad de Palermo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Use of Pd/activated carbon fiber catalyst to dehydrogenate cyclohexane

In this work, activated carbon fibers (ACFs) were prepared from polyacrylonitrile fibers, Pd catalyst was loaded onto the ACFs. The BET surface areas noted before activation were in the range of 120-140 m2/g. Activation of the fibers with carbon dioxide increased the surface areas of the fibers to about 150-190 m2/g. Diameters of metallic Pd particles loaded along the fibers ranged from 50 nm to 100 nm. The shape of the Pd particles was generally spherical albeit some non-spherical Pd particles were also noted. The catalytic activity of the Pd/ACF system in dehydrogenating cyclohexane at 350oC under liquid-phase conditions was investigated. Utilizing the Pd/ACF system in the micro-autoclave of a differential scanning calorimetric system was described for the liquid-phase catalytic dehydrogenation of cyclohexane. The DSC thermogram of the non-catalytic system yielded fewer endothermic events compared to the catalytic dehydrogenation of cyclohexane in the presence of Pd/ACF. The dehydrogenation of cyclohexane at 350oC was a first-order reaction with a rate constant, k = 3.5 x 10-4 s-1. GC-MS analyses of the products of catalytic dehydrogenation revealed a wide distribution of saturated and unsaturated hydrocarbons that were not present in the corresponding non-catalytic experiment. The presence of high molecular weight products could be explained by the recombination of carbon radicals during reaction

Jaynes Cummings Photonic Superlattices

A classical realization of the Jaynes-Cummings (JC) model, describing the interaction of a two-level atom with a quantized cavity mode, is proposed based on light transport in engineered waveguide superlattices. The optical setting enables to visualize in Fock space dynamical regimes not yet accessible in quantum systems, providing new physical insights into the deep strong coupling regime of the JC model. In particular, bouncing of photon number wave packets in Hilbert space and revivals of populations are explained as generalized Bloch oscillations in an inhomogeneous tight-binding lattice.Comment: 4 pages, 3 figure