Critical Behavior of an Ising System on the Sierpinski Carpet: A Short Time Dynamical Study

M. A. BAB; G. FABRICIUS; E. V. ALBANO

PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS

American Physical Society

Lugar: New York; Año: 2005 vol. 71 p. 1 - 9

1063-651X

The short time dynamic evolution of an Ising model embedded in an infinitely ramified fractal structure with noninteger Hausdorff dimension has been studied using Monte Carlo simulations. Completely ordered and disordered spin configurations have been used as initial states for the dynamic simulations. In both cases, the evolution of the physical observables follows a power law behavior. Based on this fact, the complete set of critical exponents characteristic of a second-order phase transition have been evaluated. Also, the dynamical exponent   of the critical initial increase of the magnetization, as well as the critical temperature, have been computed. The exponent   exhibits a weak dependence on the initial (small) magnetization. On the other hand, the dynamical exponent z shows a systematic decrease when the segmentation step is increased, i.e. when the system size becomes larger. Our results suggest that the effective noninteger dimension for the second-order phase transition is noticeable smaller than the Hausdorff dimension.