Azimuthal distinguishability of entangled photons generated in spontaneous parametric down-conversion

We experimentally demonstrate that paired photons generated in different sections of a down-conversion cone, when some of the interacting waves show Poynting vector walk-off, carry different spatial correlations, and therefore a different degree of spatial entanglement. This is shown to be in agreement with theoretical results. We also discuss how this azimuthal distinguishing information of the down-conversion cone is relevant for the implementation of quantum sources aimed at the generation of entanglement in other degrees of freedom, such as polarization.Comment: 7 pages, 5 figures, submitted to Opt. Expres

Shape of the spatial mode function of photons generated in noncollinear spontaneous parametric downconversion

We show experimentally how noncollinear geometries in spontaneous parametric downconversion induce ellipticity of the shape of the spatial mode function. The degree of ellipticity depends on the pump beam width, especially for highly focused beams. We also discuss the ellipticity induced by the spectrum of the pump beam

100 MHz Amplitude and Polarization Modulated Optical Source for Free-Space Quantum Key Distribution at 850 nm

We report on an integrated photonic transmitter of up to 100 MHz repetition rate, which emits pulses centered at 850 nm with arbitrary amplitude and polarization. The source is suitable for free space quantum key distribution applications. The whole transmitter, with the optical and electronic components integrated, has reduced size and power consumption. In addition, the optoelectronic components forming the transmitter can be space-qualified, making it suitable for satellite and future space missions.Comment: 6 figures, 2 table

Accumulation and distribution of diterpenic acids in leaves of Montanoa tomentosa

Montanoa tomentosa has been used for at least last five centuries in traditional medicine in Mexico as a remedy for reproductive impairments. The accumulation of diterpenic acids in M. tomentosa leaves was determined. Using Scanning Electron Microscopy, the type and distribution of glandular trichomes (GTs) was observed on the abaxial and adaxial sides of leaves. GTs and non-glandular trichomes (NGTs) were observed on leaf surface, but the latter are confined to the leaves abaxial side. On the adaxial surface, only non-glandular trichomes were observed. Accumulation in GTs and leaf lamina of kaurenoic (KA) and grandiflorenic (GFA) acids was determined by Gas Chromatography coupled to an Electron Impact Mass Spectrometric Detector (GC/EI-MSD). GC-MSD analysis indicated that GTs accumulated KA and GFA, with KA accumulation being at a higher level than GFA in these structures. Attention on GFA and KA is due to their importance as plant growth regulator precursors with potential pharmacological applications.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Accumulation and distribution of diterpenic acids in leaves of Montanoa tomentosa

Montanoa tomentosa has been used for at least last five centuries in traditional medicine in Mexico as a remedy for reproductive impairments. The accumulation of diterpenic acids in M. tomentosa leaves was determined. Using Scanning Electron Microscopy, the type and distribution of glandular trichomes (GTs) was observed on the abaxial and adaxial sides of leaves. GTs and non-glandular trichomes (NGTs) were observed on leaf surface, but the latter are confined to the leaves abaxial side. On the adaxial surface, only non-glandular trichomes were observed. Accumulation in GTs and leaf lamina of kaurenoic (KA) and grandiflorenic (GFA) acids was determined by Gas Chromatography coupled to an Electron Impact Mass Spectrometric Detector (GC/EI-MSD). GC-MSD analysis indicated that GTs accumulated KA and GFA, with KA accumulation being at a higher level than GFA in these structures. Attention on GFA and KA is due to their importance as plant growth regulator precursors with potential pharmacological applications.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Vortices in atomic-molecular Bose-Einstein condensates

The structure and stability of vortices in hybrid atomic-molecular Bose-Einstein condensates is analyzed in the framework of a two-component Gross-Pitaevskii-type model that describes the stimulated Raman-induced photoassociation process. New types of topological vortex states are predicted to exist in the coherently coupled two-component condensates even without a trap, and their nontrivial dynamics in the presence of losses is demonstrated.Comment: 7 pages, 6 figure

Efectos de un programa de actividad física con el método pilates sobre la funcionalidad de mujeres embarazadas. Estudio piloto

This study aims to determine the effect of a Pilates programme on functionality in pregnant women; and to analyse its impact on childbirth. A group of 10 pregnant women developed a Pilates program for 8 weeks (2 sessions/week), overall functionality was assessed through functional tests Overhead Squat (OHS), Hurdle Step (HS), Forward Step Down (FSD), Shoulder Mobility (SM) and Active Straight Leg Raise (ASLR), as well as the type of subsequent delivery. The results show an improvement in the functionality of the Hurdle test; Forward step down and Shoulder mobility test (p<0.01), as well as a significant decrease in compensation and overall risk of injury after the physical activity programme (p<0.01). In turn, the delivery was healthier. The effects of Pilates on pregnant women offer improvements in overall functionality and a positive effect on childbirth.El presente estudio pretende determinar el efecto de un programa de Pilates sobre la funcionalidad en mujeres gestantes y analizar su repercusión en el parto. Un grupo de 10 mujeres embarazadas desarrollaron un programa de Pilates durante 8 semanas (2 sesiones/semana), se valoró la funcionalidad global a través de los test funcionales Overhead Squat (OHS), Hurdle Step (HS), Forward Step Down (FSD); Shoulder Mobility (SM) y Active Straight Leg Raise (ASLR), así como el tipo de parto posterior. Los resultados muestran una mejora de la funcionalidad del Hurdle test, Forward step down  y Shoulder mobility test (p<0,01), así como un descenso significativo de las compensaciones y riesgo de lesión global después del programa de actividad física (p<0,01). A su vez, se tuvo un parto más saludable. Los efectos del Pilates en mujeres embarazadas, ofrecen mejoras en la funcionalidad global y un efecto positivo en el parto

Experimental estimation of the dimension of classical and quantum systems

An overwhelming majority of experiments in classical and quantum physics make a priori assumptions about the dimension of the system under consideration. However, would it be possible to assess the dimension of a completely unknown system only from the results of measurements performed on it, without any extra assumption? The concept of a dimension witness answers this question, as it allows one to bound the dimension of an unknown classical or quantum system in a device-independent manner, that is, only from the statistics of measurements performed on it. Here, we report on the experimental demonstration of dimension witnesses in a prepare and measure scenario. We use pairs of photons entangled in both polarization and orbital angular momentum to generate ensembles of classical and quantum states of dimensions up to 4. We then use a dimension witness to certify their dimensionality as well as their quantum nature. Our results open new avenues for the device-independent estimation of unknown quantum systems and for applications in quantum information science.Comment: See also similar, independent and jointly submitted work of J. Ahrens et al., quant-ph/1111.127

Triggered qutrits for Quantum Communication protocols

A general protocol in Quantum Information and Communication relies in the ability of producing, transmitting and reconstructing, in general, qunits. In this letter we show for the first time the experimental implementation of these three basic steps on a pure state in a three dimensional space, by means of the orbital angular momentum of the photons. The reconstruction of the qutrit is performed with tomographic techniques and a Maximum-Likelihood estimation method. In this way we also demonstrate that we can perform any transformation in the three dimensional space

An Experimental Investigation of the Adsorption of a Phosphonic Acid on the Anatase TiO2(101) Surface

A combination of synchrotron radiation photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has been used to study the adsorption of phenylphosphonic acid (PPA) on anatase TiO2(101) single crystal at coverages of 0.15 monolayer (ML) and 0.85 ML. The photoelectron spectroscopy data suggest that at 0.15 ML coverage PPA adsorbs in a bidentate geometry following deprotonation of both phosphonate hydroxyl groups, leaving the P═O group unbound. At 0.85 ML there is a shift to a mixed bidentate/monodentate binding mode. The carbon K-edge NEXAFS spectra were recorded at two azimuths. Our calculations show that for PPA on anatase TiO2(101) the phenyl ring is oriented 65 ± 4° away from the surface plane with an azimuthal twist of 57 ± 11° away from the [101] azimuth