225 research outputs found

    Universality of Schmidt decomposition and particle identity

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    Schmidt decomposition is a widely employed tool of quantum theory which plays a key role for distinguishable particles in scenarios such as entanglement characterization, theory of measurement and state purification. Yet, its formulation for identical particles remains controversial, jeopardizing its application to analyze general many-body quantum systems. Here we prove, using a newly developed approach, a universal Schmidt decomposition which allows faithful quantification of the physical entanglement due to the identity of particles. We find that it is affected by single-particle measurement localization and state overlap. We study paradigmatic two-particle systems where identical qubits and qutrits are located in the same place or in separated places. For the case of two qutrits in the same place, we show that their entanglement behavior, whose physical interpretation is given, differs from that obtained before by different methods. Our results are generalizable to multiparticle systems and open the way for further developments in quantum information processing exploiting particle identity as a resource

    Integrated Generation of High-dimensional Entangled Photon States and Their Coherent Control

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    We demonstrate the generation of high-dimensional entangled photon pairs with a Hilbert-space dimensionality larger than 100 from an on-chip nonlinear microcavity, and introduce a coherent control scheme using standard telecommunications components

    Vegetative growth and water use characterization of a maize introgression library

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    Previous work showed that a maize introgression library (IL) derived from the cross between Gasp\ue9 Flint (an early flowering Canadian landrace) and B73 (the reference maize line) segregated for phenology as well for seminal root architecture (SRA) traits. In this experiment, the IL was evaluated in the high-throughput phenotyping platform PhenoArch (INRA, Montpellier

    Scalable and effective multi-level entangled photon states: A promising tool to boost quantum technologies

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    Multi-level (qudit) entangled photon states are a key resource for both fundamental physics and advanced applied science, as they can significantly boost the capabilities of novel technologies such as quantum communications, cryptography, sensing, metrology, and computing. The benefits of using photons for advanced applications draw on their unique properties: photons can propagate over long distances while preserving state coherence, and they possess multiple degrees of freedom (such as time and frequency) that allow scalable access to higher dimensional state encoding, all while maintaining low platform footprint and complexity. In the context of out of-lab use, photon generation and processing through integrated devices and off-the-shelf components are in high demand. Similarly, multi-level entanglement detection must be experimentally practical, i.e., ideally requiring feasible single-qudit projections and high noise tolerance. Here, we focus on multi-level optical Bell and cluster states as a critical resource for quantum technologies, as well as on universal witness operators for their feasible detection and entanglement characterization. Time-and frequency-entangled states are the main platform considered in this context. We review a promising approach for the scalable, cost-effective generation and processing of these states by using integrated quantum frequency combs and fiber-based devices, respectively. We finally report an experimentally practical entanglement identification and characterization technique based on witness operators that is valid for any complex photon state and provides a good compromise between experimental feasibility and noise robustness. The results reported here can pave the way toward boosting the implementation of quantum technologies in integrated and widely accessible photonic platforms

    Scaling On-Chip Entangled Photon States to Higher Dimensions

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    Considerable efforts have recently focused on advancing quantum information pro- cessing by increasing the number of qubits (the simplest unit of quantum information) in nonclassical systems such as ultracold atoms and superconducting circuits. A complementary approach to scale up infor- mation content is to move from two-level (qubit) to multilevel (quDit) systems

    Moscato Cerletti, a rediscovered aromatic cultivar with oenological potential in warm and dry areas

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    Baron Antonio Mendola was devoted to the study of grapevine, applying ampelography and dabbling in crosses between cultivars in order to select new ones, of which Moscato Cerletti, obtained in 1869, was the most interesting. Grillo, one of the most important white cultivars in Sicily, was ascertained to be an offspring of Catarratto Comune and Zibibbo, the same parents which Mendola claimed he used to obtain Moscato Cerletti. Thus the hypothesis of synonymy between Moscato Cerletti and Grillo or the same parentage for both sets of parents needs to be verified. In the present study, historical documents were consulted and genetic analyses and ampelographic, agronomic and qualitative characterisation carried out to determine the distinctiveness of each cultivars. These were also compared with Catarratto Comune and Zibibbo in order to establish the Moscato Cerletti pedigree. Due to their different SSR profiles, Grillo and Moscato Cerletti were confirmed as two distinct cultivars; they also differed in ripening times and sugar storage ability, as well as in the aromatic grape produced by Moscato Cerletti only. The trio genotype genetic analysis confirmed that Zibibbo is a parent of Moscato Cerletti (justifying the aromatic grape), whilst the SSR profiles did not show Catarratto Comune to be a second parent. Moscato Cerletti was found to have oenological potential in the production of sparkling muscat wines due to its ability to adapt to a changing climate in warm and dry environments and in different winegrowing regions

    Red-list status and extinction risk of the world’s whales, dolphins and porpoises

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    To understand the scope and scale of the loss of biodiversity, tools are required that can be applied in a standardized manner to all species globally, spanning realms from land to the open ocean. We used data from the International Union for the Conservation of Nature Red List to provide a synthesis of the conservation status and extinction risk of cetaceans. One in 4 cetacean species (26% of 92 species) was threatened with extinction (i.e., critically endangered, endangered, or vulnerable) and 11% were near threatened. Ten percent of cetacean species were data deficient, and we predicted that 2–3 of these species may also be threatened. The proportion of threatened cetaceans has increased: 15% in 1991, 19% in 2008, and 26% in 2021. The assessed conservation status of 20% of species has worsened from 2008 to 2021, and only 3 moved into categories of lesser threat. Cetacean species with small geographic ranges were more likely to be listed as threatened than those with large ranges, and those that occur in freshwater (100% of species) and coastal (60% of species) habitats were under the greatest threat. Analysis of odontocete species distributions revealed a global hotspot of threatened small cetaceans in Southeast Asia, in an area encompassing the Coral Triangle and extending through nearshore waters of the Bay of Bengal, northern Australia, and Papua New Guinea and into the coastal waters of China. Improved management of fisheries to limit overfishing and reduce bycatch is urgently needed to avoid extinctions or further declines, especially in coastal areas of Asia, Africa, and South America.Publisher PDFPeer reviewe

    Effects of vessel traffic on relative abundance and behaviour of cetaceans : the case of the bottlenose dolphins in the Archipelago de La Maddalena, north-western Mediterranean sea

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    Acknowledgements This study was part of the Tursiops Project of the Dolphin Research Centre of Caprera, La Maddalena. Financial and logistical support was provided by the Centro Turistico Studentesco (CTS) and by the National Park of the Archipelago de La Maddalena. We thank the Natural Reserve of Bocche di Bonifacio for the support provided during data collection. The authors thank the numerous volunteers of the Caprera Dolphin Research Centre and especially Marco Ferraro, Mirko Ugo, Angela Pira and Maurizio Piras whose assistance during field observation and skills as a boat driver were invaluable.Peer reviewedPostprin
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