LOCALIZATION TRANSITION OF A DYNAMIC REACTION FRONT

We study the reaction-diffusion process A + B --> O with injection of each species at opposite boundaries of a one-dimensional lattice and b ulk driving of each species in opposing directions with a hardcore int eraction. The system shows the novel feature of phase transitions betw een localized and delocalized reaction zones as the injection rate or reaction rate is varied. An approximate analytical form for the phase diagram is derived by relating both the domain of reactants A and the domain of reactants B to asymmetric exclusion processes with open boun daries, a system for which the phase diagram is known exactly, giving rise to three phases. The reaction zone width w is described by a fini te size scaling form relating the early time growth, relaxation time a nd saturation width exponents. In each phase the exponents are distinc t from the previously studied case where the reactants diffuse isotrop ically.