title: Universal scaling effects of a temperature gradient at first-order transitions.
abstract: We study the effects of smooth inhomogeneities at first-order transitions. We show that a temperature gradient at a thermally driven first-order transition gives rise to nontrivial universal scaling behaviors with respect to the length scale l_{t} of the variation of the local temperature T_{x}. We propose a scaling ansatz to describe the crossover region at the surface where T_{x}=T_{c}, where the typical discontinuities of a first-order transition are smoothed out. The predictions of this scaling theory are checked, and get strongly supported, by numerical results for the two-dimensional (2D) Potts models, for a sufficiently large number of states to have first-order transitions. Comparing with analogous results at the 2D Ising transition, we note that the scaling behaviors induced by a smooth inhomogeneity appear quite similar in first-order and continuous transitions.
authors.affiliation: Dipartimento di Fisica dell'Università di Pisa and INFN, Largo Pontecorvo 3, I-56127, Pisa, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bonati
authors.affiliation: Dipartimento di Fisica dell'Università di Pisa and INFN, Largo Pontecorvo 3, I-56127, Pisa, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: D'Elia
authors.affiliation: Dipartimento di Fisica dell'Università di Pisa and INFN, Largo Pontecorvo 3, I-56127, Pisa, Italy.
authors.forename: Ettore
authors.initials: E
authors.lastname: Vicari
mesh_terms: D008962:Models, Theoretical; D044367:Phase Transition; D013696:Temperature