A semi-flexible attracting segment model of two-dimensional polymer collapse

Recently it has been shown that a two-dimensional model of self-attracting polymers based on attracting segments displays two phase transitions, a θθ-like collapse between swollen polymers and a globular state and another between the globular state and a polymer crystal. On the other hand, the canonical model based on attracting monomers on lattice sites displays only one: the standard tricritical θθ collapse transition. Here we consider the attracting segment model with the addition of stiffness and show that it displays the same phases as the canonical model.