Abstract
We study a system of particles with nearest- and next-nearest-neighbor exclusion on the square lattice (hard squares). This system undergoes a transition from a fluid phase at low density to a columnar-ordered phase at high density. We develop a systematic high-activity perturbation expansion for the free energy per site about a state with perfect columnar order. We show that the different terms of the series can be regrouped to get a Mayer-like series for a polydisperse system of interacting vertical rods in which the th term is of order , where is the fugacity associated with each particle. We sum this series to get the exact expansion to order .
- Received 19 April 2012
DOI:https://doi.org/10.1103/PhysRevE.86.031135
©2012 American Physical Society