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We propose and analyze a quantum synchronization sharing scheme among the nodes of a star-type quantum network. Utilizing dark state resonances, we show the biggish differences between two subsystems can be corrected by magnified effective coupling although each subsystem is of relative weak coupling intensity and high dissipation effects. Moreover, we elucidate that the quantum synchronization contains available classical and quantum correlations simultaneously. In particular, synchronization measure shows high consistency with quantum concurrence for qubit system, which means it possesses nonlocality and can ensure the advantage of quantum information processing. Finally, a brief discussion about parameter selection is given so that our scheme can be applied expediently in relevant experiments. [ABSTRACT FROM AUTHOR]

Abstract: For the sliding mode controller of uncertain chaotic systems subject to input nonlinearity, the upper bound of the norm of uncertainties is commonly used to determine the controller parameter. However, this will cause serious chattering. In order to overcome this drawback, two new sliding mode controllers are proposed to ensure robust synchronization for a classes of chaotic systems with input nonlinearities and external uncertainty. Compared with the existing results, the proposed controllers can effectively reduce the chattering nearby sliding mode and improve the dynamic performance of the systems. Simulation results are provided to verify the proposed methods. [Copyright &y& Elsevier]

Abstract: A new adaptive controller is designed to synchronize of a unified chaotic system with uncertainty (unknown parameter, noise perturbation, etc.). It is implemented by using variable structure control. The controller designed here only uses the derivative information of the uncertainty. Even if the uncertainty is time-varying or unbounded, as long as its derivative is bounded, the adaptive controller can guarantee the synchronization of the unified chaotic system with uncertainty. Finally, digital simulation is carried out for Lorenz system, and the results verify the effectiveness of the proposed method. [Copyright &y& Elsevier]

Abstract: This paper investigates the chaos synchronization problem for drive-response Chua’s systems coupled with dead-zone nonlinear input. An estimator of unknown nonlinear term is proposed. Using the sliding mode control technique and the estimate of unknown nonlinear term, a novel variable structure controller which guarantees projective synchronization even when the dead-zone nonlinearity is present. Computer simulations are provided to demonstrate the effectiveness of the proposed synchronization scheme. [Copyright &y& Elsevier]