Macro-Experimental Observation of the Staggered Mode in Lattice System

The staggered mode of solitons in polyacetylene which is first discovered by Sun et al. is one of the typical gap soliton studied in lattice system. Using a one dimensional damped and parametrically driven pendulum lattice, we have observed a stable staggered mode which can be explained successfully by a nonlinear Schrödinger equation under the multiple scale approximation.