1,354,387 research outputs found
Quantum process matrices as images: New tools to design novel denoising methods
No full textInferring a process matrix characterizing a quantum channel from experimental measurements is a key issue of quantum information. Noise affecting the measured counts could bring to matrices different from the expected ones and optimization methods usually employed, i.e. the maximum likelihood estimation (MLE), are characterized by several drawbacks. Lowering the noise could be necessary to increase the experimental resources, e.g. time for each measurement. In this paper, an alternative procedure, based on suitable Neural Networks, has been implemented and optimized to obtain a denoised process matrix and this approach has been tested with a specific quantum channel, i.e. a Control Phase. This promising method relies on the analogy that can be established between the elements of a process matrix and the pixels of an image
Extremal quantum correlations: Experimental study with two-qubit states
No full textWe explore experimentally the space of two-qubit quantum-correlated mixed states, including frontier states as defined by the use of quantum discord and von Neumann entropy. Our experimental setup is flexible enough to allow for high-quality generation of a vast variety of states. We address quantitatively the relation between quantum discord and a recently suggested alternative measure of quantum correlations
Experimental Bell inequality violation without the postselection loophole
No full textWe report on an experimental violation of the Bell-Clauser-Horne-Shimony-Holt (Bell-CHSH) inequality using energy-time-entangled photons. The experiment is not free of the locality and detection loopholes but is the first violation of the Bell-CHSH inequality using energy-time entangled photons which is free of the postselection loophole described by Aerts et al. [Phys. Rev. Lett. 83, 2872 (1999)]
Multipath entanglement of two photons
No full textWe present a novel optical device based on an integrated system of microlenses and single-mode optical fibers. It allows us to collect and direct into many modes two photons generated by spontaneous parametric down-conversion. By this device multiqubit entangled states and/or multilevel qudit states of two photons, encoded in the longitudinal momentum degree of freedom, are created. The multipath photon entanglement realized by this device is expected to find important applications in modern quantum information technology
Tomographic characterisation of correlations in a photonic tripartite state
No full textStarting from a four-partite photonic hyper-entangled Dicke resource, we report the full tomographic characterization of three-, two-, and one-qubit states obtained by projecting out part of the computational register. The reduced states thus obtained correspond to fidelities with the expected states larger than 87%, therefore certifying the faithfulness of the entanglement-sharing structure within the original four-qubit resource. The high quality of the reduced three-qubit state allows for the experimental verification of the Koashi-Winter relation for the monogamy of correlations within a tripartite state. We show that, by exploiting the symmetries of the three-qubit state obtained upon projection over the four-qubit Dicke resource, such relation can be experimentally fully characterized using only 5 measurement settings. We highlight the limitations of such approach and sketch an experimentally-oriented way to overcome them
An assessment of Diploknema butyracea (Roxb.) H. J. Lam (Chiuri) utilization in Chepang community Chitwan district, Nepal
No full textChiuri (Diploknema butyracea) is a medium-sized tree indigenous to Nepal and integral to the Chepang ethnic group. The utilization of Chiuri has experienced a decline, leading to a perceptible gap between agricultural practitioners and entrepreneurial endeavors within the Chepang community. This study, conducted from January to July 2023 in the Rapti municipality of the Chitwan district, Nepal, aims to document both traditional and contemporary applications of Chiuri in the Chepang community, evaluating its market presence, economic contributions, and cultural practices. The research involved household surveys and six key informant interviews, employing structured and semi-structured questionnaires for primary data collection. The collected data underwent meticulous analysis using MS-Excel and statistical tools. Traditionally, the Chepang community employed Chiuri for diverse purposes, including the extraction of Chiuri butter, utilization of flower juice, leaf plate fabrication, liso production, and oilcake processing. However, contemporary practices have witnessed a transition towards packaged oil, various juice derivatives, and fertilizer. Historically, Chiuri butter held paramount importance as the primary source of income for the Chepang community, supplemented by revenue generated from honey, oilcake, leaf plate crafting, alcohol juice production, and liso manufacturing. Over the past two decades, a marked decline is evident, with only 36% of the population currently engaged in processing and selling Chiuri products, compared to 85% in the past. Market transactions predominantly occur in Lothar Bazaar, trailed by Bhandara and local markets, where Chiuri butter, honey, and seeds are the primary commodities. Beekeeping, honey production and butter have emerged as the predominant sources of income. Historically vital for the economic and social well-being of the Chepang community, Chiuri has seen a decline in traditional practices such as Chepuwa (Khalang) oil extraction and a diminishing prevalence of the dowry system. Adopting cost-effective treatment technology is crucial to replace traditional methods and ensure sustainable Chiuri product production
Chiuri: The butter tree of Nepal
Get PDFThe Chiuri tree is a medium sized tree native to Nepal. It grows mainly in the sub-Himalayan tracts on steep slopes, ravines and cliffs at an altitude of 400 to 1400 metres, particularly in the Chitwan district. Its botanical name is Diploknema butvracea Roxb syn. Bassia butyracea, syn. Madhuca butyracea, syn. Aesandra butyrace
Engineering a C-phase quantum gate: Optical design and experimental realization
No full textA two qubit quantum gate, namely the C-phase, has been realized by exploiting the longitudinal momentum (i.e. the optical path) degree of freedom of a single photon. The experimental setup used to engineer this quantum gate represents an advanced version of the high stability closed-loop interferometric setup adopted to generate and characterize 2-photon 4-qubit phased Dicke states. Some experimental results, dealing with the characterization of multipartite entanglement of the phased Dicke states are also discussed in detail. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2012
Chiuri (Aesandra butyracea) and Beekeeping for Sustainable Livelihoods of Chepang Community in Raksirang-6, Makawanpur, Nepal
Get PDFChiuri trees and beekeeping are the major sources of livelihood among the Chepang community. The study was performed to assess the role of Chiuri on livelihood improvement of the Chepang community through beekeeping and to analyze the efforts of CFUGs to conserve the Chiuri in Silinge Community Forest User Group, Raksirang-6, Makawanpur district, Nepal. Focus Group Discussion, Key Informant Survey and Individual interview in households were carried out for the study from January to March 2019. With the increasing demand for organic honey made from Chiuri, the locals of the Chepang village in Makawanpur have started generating a good income from beekeeping. The majority (63%) of the respondents reported that the trends of the status of beekeeping were increasing in households. The selling of honey was the main source of income for the people of Silinge CFUGs. 1/3 of households earned the money in the range of NRs 200,000 (US 2,581.24). Physical capital and financial capital have significantly increased, whereas human, social and natural capitals were in increasing trends. The relationship between Chiuri and honey bees was very positive for both. The marketing system of Chiuri is not well developed in the study area. The Chepang community will get more prices after certifying their products as organic. Organic Certification of Nepal (OCN) should conduct studies about organic honey
Experimental realization of the Deutsch-Jozsa algorithm with a six-qubit cluster state
No full textWe describe an experimental realization of the Deutsch-Jozsa quantum algorithm to evaluate the properties of a two-bit Boolean function in the framework of one-way quantum computation. For this purpose, a two-photon six-qubit cluster state was engineered. Its peculiar topological structure is the basis of the original measurement pattern allowing the algorithm realization. The good agreement of the experimental results with the theoretical predictions, obtained at ~1 kHz success rate, demonstrates the correct implementation of the algorithm
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