Termination of pinned spirals by local stimuli
1 Department of Physics, Hangzhou Dianzi University - Hangzhou, 310018, China
2 Department of Physics, Lanzhou University of Technology - Lanzhou, 730050, China
Received: 9 January 2016
Accepted: 15 February 2016
The termination of pinned spirals on a defect by means of local stimuli is studied. On a completely unexcitable defect, the elimination process is discussed and its corresponding mechanism is presented. Especially, the mechanism of unpinning spirals on a partially unexcitable defect, which has not been investigated so far, is explored. With fixed pacing frequency ωL, there exists a maximal radius Rmax above which the pinned spiral cannot be removed. It is found that the value of Rmax does not increase as ωL in a dynamical regime, forming a platform in the curves. Based on analyzing the dispersion relation on the spiral tip around the obstacle, the underlying mechanism is clarified. Also, it is found that when multiple spirals are pinned, the value of Rmax decreases on a partially unexcitable defect while the change is very slight on a completely unexcitable one.
PACS: 87.19.Hh – Cardiac dynamics / 82.40.Ck – Pattern formation in reactions with diffusion, flow and heat transfer / 47.54.-r – Pattern selection; pattern formation
© EPLA, 2016