Modeling displaced squeezed number states in waveguide arrays

We present an exact analytical solution for a one-dimensional zigzag waveguide array with first and second neighbor interactions. It is found that the waveguide system possess a classical analog to the displaced squeezed number states. The exact solution was compared directly with the numerical solution showing a perfect agreement between both results. The implication of a linear index of refraction changing as a function of the site number is also studied. In this case, we show that the first neighbor interaction strongly influences the periodicity of Bloch oscillations.Comment: 15 pages, 9 figure

Caracterización y conservación de la piedra usada en la Catedral de Granada, España

This paper summarizes a study carried out on the Granada Cathedral which includes studies of indicators, factors and mechanisms of deterioration. A complete chemical and physical characterization of altered and unaltered material from the quarries and the building has been made. Eight commercial treatment products have been tested on the main stone-type used in the monument, including two accelerated weathering tests (salt crystallization and SO2 chemical attack). Some conservation proposals have been made.Este artículo recoge un estudio llevado a cabo sobre la Catedral de Granada que incluye la determinación de los indicadores, factores y mecanismos de deterioro. Asimismo se ha realizado una completa caracterización física y química del material alterado del edificio e inalterado de cantera. Se han probado ocho productos comerciales aplicados al principal tipo de piedra existente en el monumento, incluyendo la realización de dos ensayos de alteración acelerada (cristalización de sales y ataque químico con atmósfera de SO2. Como punto final se recogen algunas recomendaciones de cara a una posible intervención

The Orbit of the New Milky Way Globular Cluster FSR1716 =VVV-GC05

Indexación: Scopus.We use deep, multi-epoch near-IR images of the VISTA Variables in the Via Lictea (VVV) Survey to measure proper motions (PMs) of stars in the Milky Way globular cluster (GC) FSR1716 = VVV-GC05. The colormagnitude diagram of this object, made by using PM-selected members, shows an extended horizontal branch, nine confirmed RR Lyrae (RRL) members in the instability strip, and possibly several hotter stars extending to the blue. Based on the fundamental-mode (ab-type) RRL stars that move coherently with the cluster, we confirmed that FSR1716 is an Oosterhoff I GC with a mean period aPabn = 0.574 days. Intriguingly, we detect tidal extensions to both sides of this cluster in the spatial distribution of PM-selected member stars. Also, one of the confirmed RRabs is located -11 arcmin in projection from the cluster center, suggesting that FSR1716 may be losing stars due to the gravitational interaction with the Galaxy. We also measure radial velocities (RVs) for five cluster red giants selected using the PMs. The combination of RVs and PMs allow us to compute for the first time the orbit of this GC, using an updated Galactic potential. The orbit results to be confined within|Zmax| < 2.0 kpc, and has eccentricity 0.4 < e < 0.6, with perigalactic distance 1.5 < Rperi (kpc) < 2.3, and apogalactic distance 5.3 < Rapo (kpc) < 6.4. We conclude that, in agreement with its relatively low metallicity ([Fe/H] =-1.4 dex), this is an inner-halo GC plunging into the disk of the Galaxy. As such, this is a unique object with which to test the dynamical processes that contribute to the disruption of Galactic GCs. © 2018. The American Astronomical Society. All rights reserved.https://iopscience.iop.org/article/10.3847/1538-4357/aacd0

Optimum parameter estimation of shaped phase objects

We show a general method to estimate with optimum precision, i.e., the best precision determined by the light-matter interaction process, a set of parameters that characterize a phase object. The method derives from ideas presented by Pezze et al., [Phys. Rev. Lett. 119, 130504 (2017)]. Our goal is to illuminate the main characteristics of this method as well as its applications to the physics community, probably not familiar with the formal quantum language usually employed in works related to quantum estimation theory. First, we derive precision bounds for the estimation of the set of parameters characterizing the phase object. We compute the Cr\`amer-Rao lower bound for two experimentally relevant types of illumination: a multimode coherent state with mean photon number N, and N copies of a multimode single-photon quantum state. We show under which conditions these two models are equivalent. Second, we show that the optimum precision can be achieved by projecting the light reflected/transmitted from the object onto a set of modes with engineered spatial shape. We describe how to construct these modes, and demonstrate explicitly that the precision of the estimation using these measurements is optimum. As example, we apply these results to the estimation of the height and sidewall angle of a cliff-like nanostructure, an object relevant in semiconductor industry for the evaluation of nanofabrication techniques.Comment: 12 pages, 2 figure

Characterisation and impact of non-uniformity on multi-junction solar cells (MJSC) caused by concentrator optics

In this work, it has been developed a method to generate non-homogeneous light patterns on multi-junction solar cells. These patterns have been generated modifying the distance between the CPV receiver and the primary optics, which is based on a Fresnel lens. In order to diminish the impact of other variables, the incident spectrum, laboratory temperature and effective concentration have been kept constant: SMRtop-mid = 1 ± 0.02, 25 ± 0.5ºC and 380 ± 3 suns, respectively. The light patterns on the top and middle subcells are measured using a CCD camera and band-pass filters. Results show that the electrical performance of the solar cells depends on the spatial and spectral profiles. The present work introduces a procedure to characterise and evaluate the impact of non-uniformities on the output of multi-junction solar cells. Nevertheless, this work is not intended to predict the actual output of the cell as a function of the light profiles, but to provide indications for possible underlying mechanisms.This work is partially funded by European Regional Development Fund (ERDF) and Spanish Economy Ministry, grant number ENE2016-78251-