Dynamical test of phase transition order

Abstract
The dynamics of the interface between an ordered phase, characterized by an order parameter, ψ, and a disordered phase where ψ=0 provide a promising, powerful tool to distinguish between continuous or second-order and weakly first-order phase transitions. We apply this idea to the nematicsmectic-A transition and find that this transition is weakly first order even when the latent heat is too small to measure.