A new type of kinetic critical phenomenon

The authors study a new critical phenomenon in an non-thermal one-dimensional lattice model. It is characterised by the transition from stability to instability of kinks between ordered states. Below the critical point, the kinks are stable and move by annihilating random walks. Above the critical point, they are unstable against creation of kink-antikink pairs. (The spontaneous production of pairs is assumed to be absent). At the critical point p=p_cr, the density of kinks decreases like n approximately t^alpha , with alpha =0.27+or-0.08. Above the critical point, the density of kinks in the stationary state is approximately (p-p_cr)^beta with beta =0.06+or-0.2. Possible extensions to two or more dimensions and possible applications are discussed.