3,951 research outputs found

    Experimental Hamiltonian Identification for Qubits subject to Multiple Independent Control Mechanisms

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    We consider a qubit subject to various independent control mechanisms and present a general strategy to identify both the internal Hamiltonian and the interaction Hamiltonian for each control mechanism, relying only on a single, fixed readout process such as σz\sigma_z measurements.Comment: submitted to Proceedings of the QCMC04 (4 pages RevTeX, 5 figures

    Subspace confinement : how good is your qubit?

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    The basic operating element of standard quantum computation is the qubit, an isolated two-level system that can be accurately controlled, initialized and measured. However, the majority of proposed physical architectures for quantum computation are built from systems that contain much more complicated Hilbert space structures. Hence, defining a qubit requires the identification of an appropriate controllable two-dimensional sub-system. This prompts the obvious question of how well a qubit, thus defined, is confined to this subspace, and whether we can experimentally quantify the potential leakage into states outside the qubit subspace. We demonstrate how subspace leakage can be characterized using minimal theoretical assumptions by examining the Fourier spectrum of the oscillation experiment

    Growth Performance of Five Bean (Phaseolus spp) Varieties as Influenced by Organic Amendment

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    The objective of this study was to investigate the influence of organic amendment on the growth performance of five bean varieties and soil chemical characteristics. From the results, the application of soil amendment had significant (P≤ 0.05) effect on bean plant girth, number of leaves, number of branches, mean number of flowers, total fresh weight and total dry weight, of the bean five varieties planted. The increase in the bean growth observed in this research can be attributed to the improvement of the soil nutrients by the compost manure. The results from this research show that organic manure can be formulated and blended from wood sawdust, palm fruit waste and poultry waste which are chiefly abundant in the Niger Delta region of Nigeria

    Experimental Demonstration of Quantum State Multi-meter and One-qubit Fingerprinting in a Single Quantum Device

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    We experimentally demonstrate in NMR a quantum interferometric multi-meter for extracting certain properties of unknown quantum states without resource to quantum tomography. It can perform direct state determinations, eigenvalue/eigenvector estimations, purity tests of a quantum system, as well as the overlap of any two unknown quantum states. Using the same device, we also demonstrate one-qubit quantum fingerprinting

    Quantum cryptography based on qutrit Bell inequalities

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    We present a cryptographic protocol based upon entangled qutrit pairs. We analyze the scheme under a symmetric incoherent attack and plot the region for which the protocol is secure and compare this with the region of violations of certain Bell inequalities

    Surface Acoustic Wave Single-Electron Interferometry

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    We propose an experiment to observe interference of a single electron as it is transported along two parallel quasi-one-dimensional channels trapped in a single minimum of a travelling periodic electric field. The experimental device is a modification of the surface acoustic wave (SAW) based quantum processor. Interference is achieved by creating a superposition of spatial wavefunctions between the two channels and inducing a relative phase shift via either a transverse electric field or a magnetic field. The interference can be used to estimate the decoherence time of an electron in this type of solid-state device

    Flexural Rigidity Evaluation of Seismic Performance of Hollow-Core Composite Bridge Columns

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    This paper investigates experimentally the seismic behavior of two hollow-core fiber-reinforced polymer-concrete-steel HC-FCS columns under cyclic loading as a cantilever. The typical precast HC-FCS member consists of a concrete wall sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner steel tube. The FRP tube provides continuous confinement for the concrete wall along the height of the column. Five large-scale HC-FCS columns were investigated during this study to estimate the effective flexural (which is an important factor to define the buckling capacity and deflection of such columns) and the effective structural stiffness of the composite columns. These columns have the same geometric properties; the only difference was in the thickness of the inner circular steel tubes and the steel tube embedded length into the footing. A three-dimensional numerical model has been developed using LS_DYNA software for modeling this large scale HC-FCS columns. The nonlinear FE models were designed and validated against experimental results gathered from HC-FCS columns tested under cyclic lateral loading and used to evaluate the effective stiffness’s results. The estimated effective stiffness results that obtained from the experimental work were compared with the FE results. This study revealed that the effective flexural and the effective structural stiffness for the HC-FCS columns need more investigation to be addressed in the standard codes. Since the embedded hollow core steel tube socket connections cannot reach the fully fixed end condition to act as a cantilever member subjected to a lateral load with a fully fixed end condition. Moreover, the effective stiffness results were found to be highly sensitive to the steel tube embedded length and slightly to the unconfined concrete strength

    The use of behaviour management techniques amongst paediatric dentists working in the Arabian region: a cross‑sectional survey study

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    Purpose The purposes of this study were to investigate paediatric dental practitioners’ training and confidence in using dental behaviour management techniques in the Arabian region and to assess the factors influencing the application of advanced behaviour management techniques. Methods: An online questionnaire was distributed to paediatric dental practitioners in the Arabian region. Data were analysed using descriptive statistics and Pearson Chi Square. Results A total of 113 responses were obtained. Of these, the majority were from Egypt (45%, n = 51). Just over half of the respondents were registered as specialists at the country where they were practicing paediatric dentistry (53%, n = 60). The use of behaviour management techniques varied amongst participants with tell-show-do (95%, n = 107) and positive reinforcement (89%, n = 101) being the most routinely used techniques. The majority of participants reported using voice control (83%) and parental separation (68%) techniques. Hand over mouth exercise (HOME) was only used by 24% (n = 27) of participants, whilst just over half of the participants, 53%, reported using protective stabilisation. A significant association was shown between country of practice, country of obtaining paediatric dental training, speciality status and the use of advanced behaviour management techniques, whilst confidence in using HOME and sedation were associated with work setting and country of practice, respectively. Conclusion The use of advanced behaviour management techniques was found to be high amongst respondents in the Arabian region. The lack of training in using these techniques, however, is of concern. Further assessment of the factors affecting the use of and confidence in applying advanced behaviour management techniques in the Arabian region is needed
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