[en] A method of the analog of electromagnetically induced transparency (EIT) in plasmonic metal–dielectric–metal (MIM) waveguide is proposed by using two asymmetric side-coupled cavities and simulated by Finite-difference time-domain (FDTD). The simulation results show that the transparency peak of EIT is very sensitive to the width difference of two cavities and the difference of coupling distances of two cavities with the bus. Furthermore, we find that high transmission of EIT-peak usually accompanies a relatively low quality factor. These properties of our novel plasmonic structure would pave the way for highly integrated optical circuits and optical information processing

[en] This paper studies the chaotic behaviours of the fractional-order unified chaotic system. Based on the approximation method in frequency domain, it proposes an electronic circuit model of tree shape to realize the fractional-order operator. According to the tree shape model, an electronic circuit is designed to realize the 2.7-order unified chaotic system. Numerical simulations and circuit experiments have verified the existence of chaos in the fraction-order unified system

[en] We rectify some errors in the scheme of generating cluster-type entangled coherent states (CTECS) proposed by Tang (2009 J. Phys. B: At. Mol. Opt. Phys. 42 085502) in this comment. Furthermore, we find that no system can successfully generate CTECS by Tang's method. (comment)

[en] Recently the performance of the quantum key distribution (QKD) is substantially improved by the decoy state method and the non-orthogonal encoding protocol, separately. In this paper, a practical non-orthogonal decoy state protocol with a heralded single photon source (HSPS) for QKD is presented. The protocol is based on 4 states with different intensities, i.e. one signal state and three decoy states. The signal state is for generating keys; the decoy states are for detecting the eavesdropping and estimating the fraction of single-photon and two-photon pulses. We have discussed three cases of this protocol, i.e. the general case, the optimal case and the special case. Moreover, the final key rate over transmission distance is simulated. For the low dark count of the HSPS and the utilization of the two-photon pulses, our protocol has a higher key rate and a longer transmission distance than any other decoy state protocol

[en] Based on the characteristic of the chaotic or hyperchaotic system and linear feedback control method, synchronization of the two identical chaotic or hyperchaotic systems with different initial conditions is studied. The range of the control parameter for synchronization is derived. Simulation results are provided to show the effectiveness of the proposed synchronization method

[en] The stability and bifurcation in a voltage controlled negative-output KY Boost converter is studied in this Letter. A glimpse at the stability and bifurcation from the power electronics simulator (PSIM) software are given. And then, its mathematical model and corresponding discrete model are derived. The stability and bifurcation of the converter are determined with the help of the loci of eigenvalues of the Jacobian matrix. It is found that the Hopf bifurcation is easy to come in this converter when the value of its energy-transferring capacitor increases. Finally, the analytical results are confirmed by the circuit experiment. - Research highlights: Stability and bifurcation of this converter are studied via the discrete model. → Hopf bifurcation occurs in this converter and low frequency oscillation appears. → There exists a jump on this converter's output voltage and it should be careful. → A compromise must be done when choosing the value of the capacitor C_b.

[en] In this paper, we numerically investigate the band-stop properties of single- or few-layers doped graphene ribbon arrays operating in the mid-infrared region by finite-difference time-domain method (FDTD). A perfect band-stop filter with extinction ratio (ER) ∼17 dB, 3 dB bandwidth ∼200 nm and the resonance notch located at 6.64 μm can be achieved. And desired working regions can be obtained by tuning the Fermi level (E _f) of the graphene ribbons and the geometrical parameters of the structure. Besides, by tuning the Fermi level of odd or even graphene ribbons with terminal gate voltage, we can achieve a dual-circuit switch with four states combinations of on-to-off. Furthermore, the multiple filter notches can be achieved by stacking few-layers structure, and the filter dips can be dynamically tuned to achieve the tunability and selective characteristics by tuning the Fermi-level of the graphene ribbons in the system. We believe that our proposal has the potential applications in selective filters and active plasmonic switching in the mid-infrared region. (paper)