Enhanced two-photon emission from a dressed biexciton

Radiative two-photon cascades from biexcitons in semiconductor quantum dots under resonant two-photon excitation are promising candidates for the generation of photon pairs. In this work, we propose a scheme to obtain two-photon emission that allows to operate under very intense driving fields. This approach relies on the Purcell enhancement of two-photon virtual transitions between states of the biexciton dressed by the laser. The richness provided by the biexcitonic level structure allows to reach a variety of regimes, from antibunched and bunched photon pairs with polarization orthogonal to the driving field, to polarization entangled two-photon emission. This evidences that the general paradigm of two-photon emission from a ladder of dressed states can find interesting, particular implementations in a variety of systems

Fansubs: Audiovisual Translation in an amateur environment

The purpose of this paper is to describe the so-called fansubs, a different type of subtitling carried out by amateur translators. The first part of this study covers both the people and phases involved in the fansubbing process from beginning to end. The second section focuses on the legality and ethics of fansubs. The third part pays attention to the actual translation of fansubs and their unique features, such as the use of translator's notes or special karaoke effects. The paper concludes with a reflection on the work done by fansubbers and the possibilities opened by this mainly Internet phenomenon

Exciting polaritons with quantum light

We discuss the excitation of polaritons---strongly-coupled states of light and matter---by quantum light, instead of the usual laser or thermal excitation. As one illustration of the new horizons thus opened, we introduce Mollow spectroscopy, a theoretical concept for a spectroscopic technique that consists in scanning the output of resonance fluorescence onto an optical target, from which weak nonlinearities can be read with high precision even in strongly dissipative environments.Comment: 5 pages, 3 figure

Identification of the optical and near-infrared counterpart of GRS 1758-258

Context. Understood to be a microquasar in the Galactic center region, GRS 1758-258 has not yet been unambiguously identified to have an optical/near-infrared counterpart, mainly because of the high absorption and the historic lack of suitable astrometric stars, which led to the use of secondary astrometric solutions. Although it is considered with 1E 1740.7-2942 as the prototypical microquasar in the Galactic center region, the Galactic origin of both sources has not yet been confirmed. Aims. We attempt to improve previous astrometry to identify a candidate counterpart to GRS 1758-258. We present observations with the Gran Telescopio de Canarias (GTC), in which we try to detect any powerful emission lines that would infer an extragalactic origin of this source. Methods. We use modern star catalogues to reanalyze archival images of the GRS 1758-258 field in the optical and near-infrared wavelengths, and compute a new astrometric solution. We also reanalyzed archival radio data of GRS 1758-258 to determine a new and more accurate radio position. Results. Our improved astrometric solution for the GRS 1758-258 field represents a significant advancement on previous works and allows us to identify a single optical/near-infrared source, which we propose as the counterpart of GRS 1758-258. The GTC spectrum of this source is however of low signal-to-noise ratio and does not rule out a Galactic origin. Hence, new spectral observations are required to confirm or discard a Galactic nature.Comment: 4 pages, 3 figures, accepted by Astronomy and Astrophysic

Corso, un buldog con ansiedad por separación

Se describe un caso de ansiedad por separación en un Buldog Francés macho de 1,7 años de edad. Sus dueños acuden a la consulta, ya que Corso destroza todo cuando se queda solo en casa. En un primer momento fue el salón, en donde fue necesario realizar obras de reparación de los destrozos provocados por el paciente. En la actualidad es un pasillo, su nueva ubicación cuando está solo. El tratamiento se compuso de tres partes: terapia farmacológica consistente en Trankimazin 1mg 1/24h y Fluoxetina 20mg 1/24h, la modificación de su entorno y una modificación de conducta, facilitada por el propio tratamiento farmacológico. Siete meses después, tras varios seguimientos, Corso es dado el alta, prolongándole el tratamiento farmacológico de Fluoxetina, media dosis durante un mes más.Privateering is described to a case of separation anxiety in a French Bulldog of 1,7 years, called Corso. The owners go to the clinic because Corso destroys everything when left alone at home. Initially was the living room where they had to make repairs of damage caused by Corso. Currently is a corridor, its new location when left alone. Treatment consisted of three parts: first the pharmacological treatment Trankimazin 1mg 1/24h and Fluoxetina 20mg 1/24h, then changing his environment and also a behavior modification helped by the pharmalogical treatment. Seven months later, and after several follow-ups, Corso was medical discharged but the pharmacological treatment was maintained for a month with half dose of Fluoxetina

Emitters of NN-photon bundles

We propose a scheme based on the coherent excitation of a two-level system in a cavity to generate an ultrabright CW and focused source of quantum light that comes in groups (bundles) of $N$ photons, for an integer $N$ tunable with the frequency of the exciting laser. We define a new quantity, the \emph{purity} of $N$-photon emission, to describe the percentage of photons emitted in bundles, thus bypassing the limitations of Glauber correlation functions. We focus on the case $1\le N\le3$ and show that close to 100% of two-photon emission and 90% of three-photon emission is within reach of state of the art cavity QED samples. The statistics of the bundles emission shows that various regimes---from $N$-photon lasing to $N$-photon guns---can be realized. This is evidenced through generalized correlation functions that extend the standard definitions to the multi-photon level.Comment: Introduce the n-th order N-photon correlation functions. Reorganized to emphasize the N-photon emitter, now extended to the antibunching regime, rather than only coherent emission as previsoul

Recurrence of the blue wing enhancements in the high ionization lines of SDSS 1004+4112 A

We present integral field spectroscopic observations of the quadruple-lensed QSO SDSS 1004+4112 taken with the fiber system INTEGRAL at the William Herschel Telescope on 2004 January 19. In May 2003 a blueward enhancement in the high ionization lines of SDSS 1004+4112A was detected and then faded. Our observations are the first to note a second event of similar characteristics less than one year after. Although initially attributed to microlensing, the resemblance among the spectra of both events and the absence of microlensing-induced changes in the continuum of component A are puzzling. The lack of a convincing explanation under the microlensing or intrinsic variability hypotheses makes the observed enhancements particularly relevant, calling for close monitoring of this object.Comment: 4 pages, 5 figure

Arcillas industriales en Aragón.

Se realiza un primer intento de tipificación, con fines industriales, de las principales formaciones arcillosas de Aragón. Se estudian las unidades más importantes de la Depresión del Ebro (Formaciones Sariñena, Longares y Series de Transición de Tarazana), de la Cordillera Ibérica (Keuper, Facies Weald y Formaciones Lignitos de Escucha y Arenas de Utrillas), los terciarios de las Depresiones Interiores (Depresiones de Calatayud y Alfambra-Teruel) y el Mioceno de la Depresión de Almazán. El mayor desarrollo lo adquieren las arcillas comunes (fundamentalmente ilíticasl. potencialmente utilizables como materiales de construcción y en alfarería. Aparecen concentraciones Importantes de arcillas especiales (sepiolita en el área de Mara y paligorskita en el área de Bordalba). En la Cordillera Ibérica destacan las arcillas caoliníferas