Kinetically induced solitons

A combination of two stochastic hopping processes is studied on a one-dimensional chain. Firstly, the particles undergo asymmetric hops with different jump lengths and rates where the principle of detailed balance is violated. The second process favours the nearest neighbour hopping whenever the next nearest sites are occupied. Due to the competition of both processes the averaged density exhibits stable solitary excitations which are induced purely by the underlying kinetics and not by forces. The numerical results are supported strongly by an analytical approach based on a quantum formulation of the master equation. Already in the simplest approximation the averaged density satisfies the Korteweg-de Vries equation with additional dissipative terms, the influence of which is discussed by scaling arguments. (author)