Exotic behavior of the reaction front in the A+B→C reaction-diffusion system

A dynamic reaction zone is produced in the A+B→C reaction-diffusion system with initially separated components. Our perturbation analysis results predict a rich behavior for the kinetics of the reaction front in the short-time limit, with variety of universality classes. In particular, we show that the center of the front can change its direction of motion. Our experimental data support this prediction and demonstrate that this behavior is measurable over a time scale of hours in bimolecular reactions at room temperature.