151 research outputs found

    On-chip III-V monolithic integration of heralded single photon sources and beamsplitters

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    We demonstrate a monolithic III-V photonic circuit combining a heralded single photon source with a beamsplitter, at room temperature and telecom wavelength. Pulsed parametric down-conversion in an AlGaAs waveguide generates counterpropagating photons, one of which is used to herald the injection of its twin into the beamsplitter. We use this configuration to implement an integrated Hanbury-Brown and Twiss experiment, yielding a heralded second-order correlation gher(2)(0)=0.10±0.02g^{(2)}_{\rm her}(0)=0.10 \pm 0.02 that confirms single-photon operation. The demonstrated generation and manipulation of quantum states on a single III-V semiconductor chip opens promising avenues towards real-world applications in quantum information

    Rapid detection of copy number variations and point mutations in BRCA1/2 genes using a single workflow by ion semiconductor sequencing pipeline

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    Molecular analysis of BRCA1 (MIM# 604370) and BRCA2 (MIM #600185) genes is essential for familial breast and ovarian cancer prevention and treatment. An efficient, rapid, cost-effective accurate strategy for the detection of pathogenic variants is crucial. Mutations detection of BRCA1/2 genes includes screening for single nucleotide variants (SNVs), small insertions or deletions (indels), and Copy Number Variations (CNVs). Sanger sequencing is unable to identify CNVs and therefore Multiplex Ligation Probe amplification (MLPA) or Multiplex Amplicon Quantification (MAQ) is used to complete the BRCA1/2 genes analysis. The rapid evolution of Next Generation Sequencing (NGS) technologies allows the search for point mutations and CNVs with a single platform and workflow. In this study we test the possibilities of NGS technology to simultaneously detect point mutations and CNVs in BRCA1/2 genes, using the OncomineTM BRCA Research Assay on Personal Genome Machine (PGM) Platform with Ion Reporter Software for sequencing data analysis (Thermo Fisher Scientific). Comparison between the NGS-CNVs, MLPA and MAQ results shows how the NGS approach is the most complete and fast method for the simultaneous detection of all BRCA mutations, avoiding the usual time consuming multistep approach in the routine diagnostic testing of hereditary breast and ovarian cancers

    Hybrid III-V/Silicon photonic circuits embedding generation and routing of entangled photon pairs

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    The demand for integrated photonic chips combining the generation and manipulation of quantum states of light is steadily increasing, driven by the need for compact and scalable platforms for quantum information technologies. While photonic circuits with diverse functionalities are being developed in different single material platforms, it has become crucial to realize hybrid photonic circuits that harness the advantages of multiple materials while mitigating their respective weaknesses, resulting in enhanced capabilities. Here, we demonstrate a hybrid III-V/Silicon quantum photonic device combining the strong second-order nonlinearity and compliance with electrical pumping of the III-V semiconductor platform with the high maturity and CMOS compatibility of the silicon photonic platform. Our device embeds the spontaneous parametric down-conversion (SPDC) of photon pairs into an AlGaAs source and their subsequent routing to a silicon-on-insulator circuitry, within an evanescent coupling scheme managing both polarization states. This enables the on-chip generation of broadband telecom photons by type 0 and type 2 SPDC from the hybrid device, at room temperature and with internal pair generation rates exceeding 10510^5 s−1s^{-1} for both types, while the pump beam is strongly rejected. Two-photon interference with 92% visibility (and up to 99% upon 5 nm spectral filtering) proves the high energy-time entanglement quality characterizing the produced quantum state, thereby enabling a wide range of quantum information applications on-chip, within an hybrid architecture merging the assets of two mature and highly complementary platforms in view of out-of-the-lab deployment of quantum technologies

    Optical sideband generation up to room temperature with mid-infrared quantum cascade lasers

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    Room temperature sideband generation on an optical carrier is demonstrated using midinfrared quantum cascade lasers. This is achieved via an enhancement of the nonlinear susceptibility via resonant interband and intersubband excitations, compensating the large phase-mismatch

    "I want to be a furious leopard with magical wings and super power": developing an ethico-interpretive framework for detecting Chinese students' funds of identity

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    The Avatar Project was a two-week English project in which Chinese high school students in an internationalised school in Shanghai China explored the topic of cultural and individual identity. The project synthesised prospective education with the Funds of Identity approach, both of which have particular relevance within an internationalised teaching context. During the project, students created three identity texts: a written reflection, a word cloud and an avatar which were later used as data for this article. This article presents findings from the project and critically evaluates the effectiveness of avatars and word clouds as strategies for detecting students’ funds of identity. A multimodal approach to data collection and analysis was adopted in order to ensure that the interpretation of students’ work remained situated within their lived experience. The project revealed the existence of social, practical, institutional and cultural funds of identity. However, it also detected more problematic forms of funds of identity related to political and philosophical beliefs which I label ideological and existential funds of identity. While avatars and word clouds were effective in drawing out students’ out-of-school identities, the written reflections were ultimately more useful in revealing students’ funds of identity and also ensuring that any interpretations remained within the participants’ horizon of intended meaning. The project also brought about significant transformation in the way I viewed my students

    Groundwater of Rome

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    This paper describes the contents of the new Hydrogeological Map of the City of Rome (1:50,000 scale). The map extends to the entire municipality (1285 km2) and is based on both the most recent scientific studies on the groundwater field and new survey activities carried out in order to fill the data gaps in several areas of the examined territory. The map is the result of a combination of different urban groundwater expertise and Geographic Information System (GIS)-based mapping performed using the most recent available data and has been produced with the intention of furnishing the City of Rome with the most recent and updated information regarding groundwater
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