The drift of spirals under competitive illumination in an excitable medium

We study numerically the resonant drift of spirals induced by periodic illuminations in excitable media for the Oregonator model. Differential phase illumination of a competitive system with an interface causes interesting spiral drift behavior which can be related to the phase difference. It is found that the drift directions and velocities have been controlled by changing their phase differences, and the spiral has been forbidden to drift back to the initial region due to the interface. Furthermore, the simulation result seems to be reliable as it is also consistent perfectly with the theoretical analysis based on the weak deformation approximation.