Phase transitions in hard core lattice gas models of anisotropic particles
Joyjit Kundu, Institute of Mathematical Sciences, Chennai
Hard core lattice gas models of particles interacting only through excluded volume interaction continue to be of interest in Statistical Physics. They are minimal models to study entropy driven phase transitions, have direct realizations in adsorption of gas particles on metal surfaces and are closely related to the freezing transition. In this talk, I will discuss the system of hard rectangles of size m x m k on a two dimensional lattice, where k is the aspect ratio. The phase diagram of this model for arbitrary m and k is determined using Monte-Carlo simulations, entropic arguments, and analytical calculations based on the Bethe approximation. In particular, it will be shown that, with increasing density, the system undergoes three entropy driven phase transitions for large enough k.