title: Formation of a spiraling line defect and its meandering transition in a period-2 medium.
abstract: The instability of a period-1 spiral wave resulting in a period-2 spiral wave with a line defect is investigated for the first time in a laboratory system. At the very onset the transition proceeds by an emergence of a spiraling line defect, "breathing" intermittently while retaining its symmetry of a period-1 spiral wave. With a further change in a control parameter, the line defect undergoes a meandering transition producing a compound tip trajectory, following a dynamic shape transition. The observed transitions have a strong analogy to the phase synchronization transition of two coupled nonlinear oscillators and the meandering transition of a period-1 spiral wave.
authors.affiliation: National Creative Research Initiative Center for Neurodynamics and Department of Physics, Korea University, Seoul 136-701, Korea.
authors.forename: Jin-Sung
authors.initials: JS
authors.lastname: Park
authors.forename: Kyoung J
authors.initials: KJ
authors.lastname: Lee