Monte Carlo study of the phase transition in the critical behavior of the Ising model with shear

G. P. SARACCO, G. GONNELLA

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

APS

Lugar: Ridge, New York; Año: 2009 vol. 80 p. 511261 - 5112610

1063-651X

he critical behavior of the Ising model with nonconserved dynamics and an external driving field mimicking a shear profile is analyzed by studying its dynamical evolution in the short-time regime. Starting from high-temperature disordered configurations (fully disordered configurations, FDC), the critical temperature Tc is determined when the order parameter, defined as the absolute value of the transversal spin profile, exhibits a power-law behavior with an exponent that is a combination of some of the critical exponents of the transition. For each value of the shear field magnitude, labeled as , Tc has been estimated and two stages have been found: (1) a growing stage at low values of , where Tc~ and =0.52(3), and (2) a saturation regime at large . The same values of Tc() were found studying the dynamical evolution from the ground-state configuration with all spins pointing in the same direction. By combining the exponents of the corresponding power laws obtained from each initial configuration, the set of critical exponents was calculated. These values, at large external field magnitude, define a critical behavior different from that of the Ising model and of other driven lattice gases.