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

G. P. Saracco, G. Gonnella

Published 2009-10-16Version 1

The critical behavior of the Ising model with non-conserved dynamics and an external shear profile is analyzed by studying its dynamical evolution in the short time regime. Starting from high temperature disordered configurations (FDC), the critical temperature $T_c$ 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 $\dot{\gamma}$, $T_c$ has been estimated and two stages have been found: 1) a growing stage at low values of $\dot{\gamma}$, where $T_c\sim\dot{\gamma}^\psi$ and $\psi=0.52(3)$; 2) a saturation regime at large $\dot{\gamma}$. The same values of $T_c(\dot{\gamma})$ were found studying the dynamical evolution from the ground state configuration (GSC) 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 new critical behavior different from that of the Ising model and of other driven lattice gases.