Dynamical study of the necklace states

Based on finite-difference-time domain methods (FDTD), we have numerically directly investigated the dynamical effects of necklace states on the transmission for one-dimensional (1D) random systems with pulsed incidence in time domain. The necklace state propagation property, which is faster than the common localized modes, is demonstrated directly. From the instantaneous decay coefficient κ(t) and the instantaneous transmittance spectrum T(τ,ω), we have constructed a dynamical picture for the random systems with necklace states. In the picture, we have explained the high plateau on the κ(t) curves by the properties of necklace states, and then defined the time range of high plateau as the “effective time range” of necklace states effects. Further more, we have confirmed the dynamical picture by the ensemble study of random configurations. For the different length, we show that the effects of necklace states will be stronger if the system is longer. Besides these, we also introduce the instantaneous decay coefficient and the instantaneous transmittance spectrum to study the dynamical effects of necklace states. This theoretical study of necklace states can be helpful not only for the deeper physical understanding of necklace states, but also for the experimental observation of necklace states.