608 research outputs found

    Dynamical Casimir effect entangles artificial atoms

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    We show that the physics underlying the dynamical Casimir effect may generate multipartite quantum correlations. To achieve it, we propose a circuit quantum electrodynamics (cQED) scenario involving superconducting quantum interference devices (SQUIDs), cavities, and superconducting qubits, also called artificial atoms. Our results predict the generation of highly entangled states for two and three superconducting qubits in different geometric configurations with realistic parameters. This proposal paves the way for a scalable method of multipartite entanglement generation in cavity networks through dynamical Casimir physics.Comment: Improved version and references added. Accepted for publication in Physical Review Letter

    The quantum Rabi model in a superfluid Bose-Einstein condensate

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    We propose a quantum simulation of the quantum Rabi model in an atomic quantum dot, which is a single atom in a tight optical trap coupled to the quasiparticle modes of a superfluid Bose-Einstein condensate. This widely tunable setup allows to simulate the ultrastrong coupling regime of light-matter interaction in a system which enjoys an amenable characteristic timescale, paving the way for an experimental analysis of the transition between the Jaynes-Cummings and the quantum Rabi dynamics using cold-atom systems. Our scheme can be naturally extended to simulate multi-qubit quantum Rabi models. In particular, we discuss the appearance of effective two-qubit interactions due to phononic exchange, among other features.Comment: Improved version and references adde

    Organizational and Technological Aspects of a Platform for Collective Food Awareness

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    Can Internet-of-food technologies foster collective food awareness within a food consumer community? The paper contributes to answer this question in a fourfold aspect. Firstly, we model a cooperative process for generating and sharing reliable food information that is derived from food instrumental measurements performed by consumers via smart food things. Secondly, we outline the functional architecture of a platform capable to support such a process and to let a consumer community share reliable food information. Thirdly, we identify main entities and their attributes necessary to model the contextualized interaction between a consumer and the platform. Lastly, we review articles reviewing technologies capable of acquiring and quantifying food characteristics for food performances assessment. The purpose is to give an insight into current research directions on technologies employable in a platform for collective food awareness

    Decision analysis for the determination of biomass in the territory Tuscia Romana by geographic information system and forest management plans

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    The growing interest in the development of chains for the use of agroforestry biomass for energy demand, is due to the awareness they are a crucial element to mitigate the global climatic change effects. The true effort is to have a reliable estimation of biomass availability by some instruments like forest management plans, which allow to locate the forest supply and to know the forest biomass availability in a medium period. In this paper we carried out a decision analysis by geographic information system, in Tuscia Romana area comprising 11 municipalities for a total amount of 813 km2. An estimation was carried out taking into account the bibliographic data on the analyzed species, reporting the biomass in weight taken out by the forest cut utilization. A comparison was also performed in field on chestnut trees cut in a sampling area near Bracciano and in a close sawmill. The results show long, medium and short-term dynamics, but some critical points were found related to the process of estimation and to the real procurement of biomass in some years. The results suggest to be care in a possible project of a biomass plant

    Polarization converter post-processing for integrated polarization independent SOA

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    Post-processing of a polarization converter (PC) in an experimental industrial generic foundry process is demonstrated. Insertion of the PC halfway an SOA reduced its polarization dependence from 14 dB to 3 dB

    Critical Quantum Metrology with a Finite-Component Quantum Phase Transition

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    Physical systems close to a quantum phase transition exhibit a divergent susceptibility, suggesting that an arbitrarily high precision may be achieved by exploiting quantum critical systems as probes to estimate a physical parameter. However, such an improvement in sensitivity is counterbalanced by the closing of the energy gap, which implies a critical slowing down and an inevitable growth of the protocol duration. Here, we design different metrological protocols that exploit the superradiant phase transition of the quantum Rabi model, a finite-component system composed of a single two-level atom interacting with a single bosonic mode. We show that, in spite of the critical slowing down, critical quantum optical probes can achieve a quantum-enhanced time scaling of the sensitivity in frequency-estimation protocols
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