Effects of a quenched disorder on wave propagation in excitable media

The behavior of autowaves under the effect of a quenched disorder is studie d in the framework of the light-sensitive Belousov-Zhabotinsky reaction. Th is allows us to introduce spatial disorder on the excitability by projectin g patterns of light transmittance. In particular, we have selected a dichot omic random distribution of levels of transmittance. If the two values of t ransmittance are equally probable and allows wave propagation without break ing the waves, we find an opposite effect on the wave front velocity and sh ape depending on the considered dimension. On the other hand, if one of the two values of the transmittance distribution is set on the nonexcitable re gion, percolation phenomena can arise by changing the number of excitable s ites. The different addressed situations are analytically interpreted givin g theoretical predictions for the experimental and numerical results.