First-order phase transitions investigated by use of a Monte Carlo interface method

We investigate first-order phase transitions on unfrustrated antiferromagnetic Potts models in two and three dimensions by estimating the interface free energy by use of a Monte Carlo method. Even for strong first-order transitions the occurrence of hysteresis is circumvented and our method allows for an accurate determination of ${\mathit{T}}_{\mathit{c}}$ by locating a \ensuremath{\delta}-function-shaped peak in the energy difference between configurations with and without an interface.