Crossover between Ising and XY -like behavior in the off-equilibrium kinetics of the one-dimensional clock model.
We study the phase-ordering kinetics following a quench to a final temperature Tf of the one-dimensional p-state clock model. We show the existence of a critical value pc=4, where the properties of the dynamics change. At Tf=0, for p<or=pc the dynamics is analogous to that of the kinetic Ising model, characterized by Brownian motion and annihilation of interfaces. Dynamical scaling is obeyed with the same dynamical exponents and scaling functions of the Ising model. For p>pc, instead, the dynamics is dominated by a texture mechanism analogous to the one-dimensional XY model and dynamical scaling is violated. During the phase-ordering process at Tf>0, before equilibration occurs, a crossover between an early XY-like regime and a late Ising-like dynamics is observed for p>pc.
Andrenacci
Natascia
N
Dipartimento di Fisica E. Caianiello and CNR-INFM Istituto Nazionale di Fisica della Materia, Università di Salerno, 84081 Baronissi (Salerno), Italy. andrenacci@sa.infn.it
Corberi
Federico
F
Lippiello
Eugenio
E