Experimental defect dynamics driven by phase gradient in liquid-crystal electro-convective patterns

In this work, we observe experimentally the dynamics of the defects of a periodic convective pattern obtained in a liquid crystal n -(4-methoxybenziliden)-4-butylamilin 98% cell subjected to electro-nematic instability by means of an ac electric field. We perform a check of the validity of the theoretical prescriptions regarding the interaction of these defects with the external phase-field gradient. We found results in a good agreement with the theory.