23 research outputs found

    Scalable Quantum Spin Networks from Unitary Construction

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    Spin network systems can be used to achieve quantum state transfer with high fidelity and to generate entanglement. A new approach to design spin-chain-based spin network systems, for shortrange quantum information processing and phase-sensing, has been proposed recently in [1]. In this paper, we investigate the scalability of such systems, by designing larger spin network systems that can be used for longer-range quantum information tasks, such as connecting together quantum processors. Furthermore, we present more complex spin network designs, which can produce different types of entangled states. Simulations of disorder effects show that even such larger spin network systems are robust against realistic levels of disorder.Comment: 17 pages, 24 figure

    Youth Volunteer Service in Latin America and the Caribbean: A Regional Assessment

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    Youth Volunteer Service in Latin America and the Caribbean: A Regional Assessmen

    Robust quantum entanglement generation and generation-plus-storage protocols with spin chains

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    Reliable quantum communication and/or processing links between modules are a necessary building block for various quantum processing architectures. Here we consider a spin-chain system with alternating strength couplings and containing three defects, which impose three domain walls between topologically distinct regions of the chain. We show that - in addition to its useful, high-fidelity, quantum state transfer properties - an entangling protocol can be implemented in this system, with optional localization and storage of the entangled states. We demonstrate both numerically and analytically that, given a suitable initial product-state injection, the natural dynamics of the system produces a maximally entangled state at a given time. We present detailed investigations of the effects of fabrication errors, analyzing random static disorder both in the diagonal and off-diagonal terms of the system Hamiltonian. Our results show that the entangled state formation is very robust against perturbations of up to ∼10% the weaker chain coupling, and also robust against timing injection errors. We propose a further protocol, which manipulates the chain in order to localize and store each of the entangled qubits. The engineering of a system with such characteristics would thus provide a useful device for quantum information processing tasks involving the creation and storage of entangled resources

    Scalable Quantum Spin Networks from Unitary Construction

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    Spin network (SN) systems can be used to achieve quantum state transfer with high fidelity and to generate entanglement. A new approach to design spin-chain-based spin network systems, for short-range quantum information processing and phase-sensing, has been proposed recently in Advanced Quantum Technologies. In this paper, the scalability of such systems is investigated, by designing larger SN systems that can be used for longer-range quantum information tasks, such as connecting together quantum processors. Furthermore, more complex SN designs, which can produce different types of entangled states, are presented. Simulations of disorder effects show that even such larger SN systems are robust against realistic levels of disorder

    Generation and robustness of quantum entanglement in spin graphs

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    Entanglement is a crucial resource for quantum information processing, and so protocols to generate high-fidelity entangled states on various hardware platforms are in demand. While spin chains have been extensively studied to generate entanglement, graph structures also have such potential; however, only a few classes of graphs have been explored for this specific task. In this paper, we apply a particular coupling scheme involving two different coupling strengths to a graph of two interconnected 3 × 3 square graphs such that it effectively contains three defects. We show how this structure allows generation of a Bell state whose fidelity depends on the chosen coupling ratio. We apply partitioned graph theory in order to reduce the dimension of the graph and show that, using a reduced graph or a reduced chain, we can still simulate the same protocol with identical dynamics. Finally, we investigate how fabrication errors affect the entanglement generation protocol and how the different equivalent structures are affected, finding that for some specific coupling ratios they are extremely robust

    Novel indolic AMPK modulators induce vasodilatation through activation of the AMPK-eNOS-NO pathway

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    Endothelial adenosine monophosphate-activated protein kinase (AMPK) plays a critical role in the regulation of vascular tone through stimulating nitric oxide (NO) release in endothelial cells. Since obesity leads to endothelial dysfunction and AMPK dysregulation, AMPK activation might be an important strategy to restore vascular function in cardiometabolic alterations. Here, we report the identification of a novel AMPK modulator, the indolic derivative IND6, which shows affinity for AMPKα1β1γ1, the primary AMPK isoform in human EA.Hy926 endothelial cells. IND6 shows inhibitory action of the enzymatic activity in vitro, but increases the levels of p-Thr174AMPK, p-Ser1177eNOS and p-Ser79ACC in EA.Hy926. This paradoxical finding might be explained by the ability of IND6 to act as a mixed-type inhibitor, but also to promote the enzyme activation by adopting two distinct binding modes at the ADaM site. Moreover, functional assays reveal that IND6 increased the eNOS-dependent production of NO and elicited a concentration-dependent vasodilation of endothelium-intact rat aorta due to AMPK and eNOS activation, demonstrating a functional activation of the AMPK-eNOS-NO endothelial pathway. This kinase inhibition profile, combined with the paradoxical AMPK activation in cells and arteries, suggests that these new chemical entities may constitute a valuable starting point for the development of new AMPK modulators with therapeutic potential for the treatment of vascular complications associated with obesity

    Anderson localisation in spin chains for perfect state transfer

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    Abstract: Anderson localisation is an important phenomenon arising in many areas of physics, andhere we explore it in the context of quantum information devices. Finite dimensional spinchains have been demonstrated to be important devices for quantum information transport,and in particular can be engineered to allow for “perfect state transfer” (PST). Here wepresent extensive investigations of disordered PST spin chains, demonstrating spatiallocalisation and transport retardation effects, and relate these effects to conventionalAnderson localisation. We provide thresholds for Anderson localisation in these finitequantum information systems for both the spatial and the transport domains. Finally, weconsider the effect of disorder on the eigenstates and energy spectrum of our Hamiltonian,where results support our conclusions on the presence of Anderson localisation. Graphical abstract: [Figure not available: see fulltext.

    Pla d’actuació per prevenir els efectes de les onades de calor sobre la salut (POCS 2019): informe de les actuacions realitzades i dels resultats obtinguts

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    Calor elevada; Mesures de prevenció; ResultatsHigh heat; Preventive measures; ResultsCalor elevada; Medidas de prevención; ResultadosEl Pla d'actuació per prevenir els efectes de les onades de calor sobre la salut (POCS) a Catalunya és un pla estacional que s'activa anualment de l'1 de juny fins al 30 de setembre. Està coordinat per l'Agència de Salut Pública de Catalunya (ASPCAT) i el Servei Català de la Salut i compta amb la participació de més d'una quinzena d'entitats. L’informe presenta les actuacions realitzades i dels resultats obtinguts en relació al pla d’actuació per prevenir els efectes de les onades de calor sobre la salut (POCS) durant l'estiu de l'any 201
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