One dimensional non-equilibrium systems with short-range interaction can
undergo phase transitions from homogeneous states to phase separated states as
interaction (ϵ) among particles is increased. One of the model systems
where such transition has been observed is the extended Katz-Lebowitz-Spohn
(KLS) model with ferro-magnetically interacting particles at ϵ=4/5.
Here, the system remains homogeneous for small interaction strength
(ϵ<4/5), and for anti-feromagnetic interactions (ϵ<0). We
show that the phase separation transitions can also occur in anti-ferromagnetic
systems if interaction among particles depends explicitly on the size of the
block (n) they belong to. We study this transition in detail for a specific
case ϵ=δ/n, where phase separation occurs for δ<−1.Comment: 4 pages, 5 figure