Cooperative Behavior in Driven Lattice Systems with Shifted Periodic Boundary Conditions

Abstract

We explore the nature of driven stochastic lattice systems with non-periodic

boundary conditions. The systems consist of particle and holes which move by

exchanges of nearest neighbor particle-hole pairs. These exchanges are

controlled by the energetics associated with an internal Hamiltonian, an

external drive and a stochastic coupling to a heat reservoir. The effect of

the drive is to bias particle-hole exchanges along the field in such a way

that a particle current can be established. Hard-core volume constraints

limit the occupation of only one particle (hole) per lattice site. For

certain regimes of the overall particle density and temperature, a system

displays a homogeneous disordered phase. We investigate cooperative behavior

in this phase by using two-point spatial correlation functions and structure

factors. By varying the particle density and the temperature, the system

orders into a phase separated state, consisting of particle-rich and

particle-poor regions. The temperature and density for the co-existence

state depend on the boundary conditions. By using Monte Carlo simulations,

we establish co-existence curves for systems with shifted periodic boundary

conditions.