Persistence exponent in a superantiferromagnetic quenching
Emilio N.M. Cirillo, Giuseppe Gonnella, Sebastiano Stramaglia
Abstract
We measure the persistence exponent in a phase separating two-dimensional spin system with non-conserved dynamics quenched in a region with four coexisting stripe phases. The system is an Ising model with nearest neighbor, next-to-the-nearest neighbor and plaquette interactions. Due the particular nature of the ground states, the order parameter is defined in terms of blocks of spins. Our estimate of the persistence exponent,
θ=0.42
, differs from those of the two-dimensional Ising and four state Potts models. Our procedure allows the study of persistence properties also at finite temperature
T
: our results are compatible with the hypothesis that
θ
does not depend on
T
below the critical point.