Critical behavior of the Ising model under strong shear: The conserved case

G. P. SARACCO; G. GONNELLA

PHYSICA A - STATISTICAL AND THEORETICAL PHYSICS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2021 vol. 576

0378-4371

The non-equilibrium phase transitions of the two-dimensional magnetization-conserved Ising model under the action of an external shear field is investigated. This field, that simulates a convective velocity profile with shear rate$dot{gamma}$, introduces anisotropic effects and forces the system to evolve into non equilibrium states. By employing the short-time dynamics (STD) methodology, it was possible to detect first- and second- order phase transitions, and in this last case the critical exponent were calculated. As a function of the absolute magnetization $|M|$ the system exhibits phase transitions of different order. On the one hand, If $|M|=0$, the model undergoes a second-order phase transition. The estimated critical temperature $T_c$ depends on $dot{gamma}$ and two regimes can be distinguished: a power-law regime for low $dot{gamma}´s$, and a saturation regime at larger values of it. For the investigated shear field interval, the estimated values of the anisotropic critical exponents suggest that the critical behavior is on a crossover between the Ising and mean-field critical behaviors, respectively. On the other hand if $|M|> 0$, the model exhibits for each $dot{gamma}$ first-order phase transitions, ending in a critical point at $|M|=0$. p, li { white-space: pre-wrap; }