Demonstration of a programmable source of two-photon multiqubit entangled states

We suggest and demonstrate a novel source of two-photon multipartite entangled states which exploits the transverse spatial structure of spontaneous parametric downconversion together with a programmable spatial light modulator (SLM). The 1D SLM is used to perform polarization entanglement purification and to realize arbitrary phase-gates between polarization and momentum degrees of freedom of photons. We experimentally demonstrate our scheme by generating two-photon three qubit linear cluster states with high fidelity using a diode laser pump with a limited coherence time and power on the crystal as low as 2.5$mW.Comment: 5 pages, 4 figures, to appear on PR

Programmable entanglement oscillations in a non Markovian channel

We suggest and demonstrate an all-optical experimental setup to observe and engineer entanglement oscillations of a pair of polarization qubits in a non-Markovian channel. We generate entangled photon pairs by spontaneous parametric downconversion (SPDC), and then insert a programmable spatial light modulator in order to impose a polarization dependent phase-shift on the spatial domain of the SPDC output and to create an effective non-Markovian environment. Modulation of the enviroment spectrum is obtained by inserting a spatial grating on the signal arm. In our experiment, programmable oscillations of entanglement are achieved, with the maximally revived state that violates Bell's inequality by 17 standard deviations.Comment: 4 pages, 4 figure

Programmable purification of type-I polarization-entanglement

We suggest and demonstrate a scheme to compensate spatial and spectral decoherence effects in the generation of polarization entangled states by type-I parametric downconversion. In our device a programmable spatial light modulator imposes a polarization dependent phase-shift on different spatial sections of the overall downconversion output and this effect is exploited to realize an effective purification technique for polarization entanglement.Comment: published versio

matteo-brv @ DaDoEval: An SVM-based Approach for Automatic Document Dating

This paper describes our contribution to the EVALITA 2020 shared task DaDoEval – Dating Document Evaluation. The solution we present is based on a linear multi-class Support Vector Machine classifier trained on a combination of character and word n-grams, as well as number of word tokens per document. Despite its simplicity, the system ranked first both in the coarse-grained classification task on same-genre data and in the one on cross-genre data, achieving a macro-average F1 score of 0.934 and 0.413, respectively. The system implementation is available at https://github.com/matteobrv/DaDoEval

Uso de TIC y aprendizaje del idioma italiano en los estudiantes en un instituto privado de idiomas de Lima, 2020

La presente investigación denominada uso de TIC y aprendizaje del idioma italiano en los estudiantes en un instituto privado de idiomas de Lima, 2020, tuvo como objetivo principal establecer cuál es la relación de la TIC en los aprendices de un segundo idioma L2, en el especifico del idioma italiano, en un instituto privado de idiomas de Lima, 2020. La tipología de investigación utilizada en la presente es de tipo aplicada, de nivel descriptivo – correlacional, con enfoque cuantitativo y diseño no experimental de corte trasversal, utilizando los instrumentos de las encuestas en línea. La población está constituida por los 807 alumnos del presente centro de idiomas en el mes de junio del 2020 y la muestra se ha calculado con una probabilidad de error del 5% y un nivel de confianza del 93,5%, por lo tanto, la muestra está compuesta da 178 alumnos. La conclusión del presente trabajo de investigación determina que existe una relación directa y significativa, bajo todas las dimensiones analizadas entre el uso de TIC en el aprendizaje del idioma italiano en los estudiantes de un instituto privado de idiomas de Lima, con el fin de poder sustituir, implementar los materiales didácticos suministrados a los aprendices, de una forma que sea más interactivo y que pueda permitir un desarrollo significativamente más alto es sus propias habilidades de producción escrita y oral en el segundo idioma estudiad

Filosofía de la educación en la era digital

El presente estudio tuvo como objetivo identificar los cambios en la filosofía de la educación en la era digital, habiéndose modificado y evolucionado de manera permanente, más aún en  estos tiempos de pandemia en la cual prima el uso de los recursos y herramientas tecnológicas como medios de aprendizaje, lo que implica un cambio en la forma de actuar de los agentes educativos. En este artículo de revisión se investigó el término en estudio, identificando los cambios que sufrió como producto de la incorporación de la tecnología en el ámbito educativo. En esta investigación se abordó la filosofía en el sector de la educación y el acceso a la educación inclusiva. A las conclusiones que la investigación arribó fueron: La filosofía en la era digital, se fue introduciendo de manera paulatina en el modo de vida y actuar de los educadores y estudiantes; por otra parte, en la literatura investigada se observa un mejor desarrollo en los países que desde una temprana edad, incorporan en sus mallas curriculares el uso de los recursos tecnológicos, lo que implica el logro de una mayor capacidad de los estudiantes para entender la realidad

Optical interferometry in the presence of large phase diffusion

Phase diffusion represents a crucial obstacle towards the implementation of high precision interferometric measurements and phase shift based communication channels. Here we present a nearly optimal interferometric scheme based on homodyne detection and coherent signals for the detection of a phase shift in the presence of large phase diffusion. In our scheme the ultimate bound to interferometric sensitivity is achieved already for a small number of measurements, of the order of hundreds, without using nonclassical light

Experimental estimation of one-parameter qubit gates in the presence of phase diffusion

We address estimation of one-parameter qubit gates in the presence of phase diffusion. We evaluate the ultimate quantum limits to precision, seek for optimal probes and measurements, and demonstrate an optimal estimation scheme for polarization qubits. An adaptive method to achieve optimal estimation in any working regime is also analyzed in details and experimentally implemented.Comment: revised version, to appear on PR

Battery modeling for microgrid design: A comparison between lithium-ion and lead acid technologies

Battery energy storage systems are fundamental components in microgrids operations, therefore it is important to adopt models suitable to properly evaluate the performance of these electrical systems. Different methodologies for battery modeling have been developed and tested in this work: (i) Empirical model, in which batteries are described by analytic expressions not based on electrochemical processes; (ii) Equivalent electrical circuit model, in which batteries are described in terms of electrical quantities. These approaches allow to adapt the model to different battery technologies: both the emerging Li-ion and the consolidated lead acid are considered in this paper. The proposed models are implemented in the software Poli. NRG, a Matlab based procedure for microgrid sizing developed by Energy Department of Politecnico di Milano. Simulations are based on a real case study relevant to a microgrid in a rural area: Ngarenanyuki Secondary School in Tanzania. The proposed methodology is used to design a new microgrid based on photovoltaic and energy storage system, comparing the results obtained adopting different modeling approaches and different technologies. Eventually, results are critically analyzed and discussed in order to compare accuracy, computational effort, costs and opportunities

A novel method to investigate how the spatial correlation of the pump beam affects the purity of polarization entangled states

We present an innovative method to address the relation between the purity of type-I polarization entangled states and the spatial properties of the pump laser beam. Our all-optical apparatus is based on a spatial light modulator, and it offers unprecedented control on the spatial phase function of the entangled states. In this way, we demonstrate quantitatively the relation between the purity of the generated state and spatial correlation function of the pump beam.Comment: 3 pages, 3 figure