Novel type of amplitude spiral wave in a two-layer system

Interaction of spiral waves in a two-layer system described by a model of coupled complex Ginzburg-Landau equations with negative-feedback couplings epsilon(1) and epsilon(2) is studied. Synchronization of two spiral waves can be broadly found if epsilon(1) + epsilon(2) is sufficiently large. Prior to the synchronization, under the condition of strongly asymmetric coupling (vertical bar epsilon(1)-epsilon(2)vertical bar >> 0), a novel type of spiral wave, amplitude spiral wave, exists in the driven system. The pattern of amplitude spiral wave shows the spiral in the amplitude and without a singularity point (tip), compared to usual spiral waves known for phase with amplitude uniform far away from tips and rotating around tips. (C) 2010 American Institute of Physics. [doi:10.1063/1.3526965]