C. S. Simoes | Searcharxiv

arXiv2001

Dynamic critical exponents of the Ising model with multispin interactions

We revisit the short-time dynamics of 2D Ising model with three spin interactions in one direction and estimate the critical exponents $z,$ $θ,$ $β$ and $ν$. Taking properly into account the symmetry of the Hamiltonian we obtain results completely different from those obtained by Wang et al.. For the dynamic exponent $z$ our result coincides with that of the 4-state Potts model in two dimensions. In addition, results for the static exponents $ν$ and $β$ agree with previous estimates obtained from finite size scaling combined with conformal invariance. Finally, for the new dynamic exponent $θ$ we find a negative and close to zero value, a result also expected for the 4-state Potts model according to Okano et al.

cond-mat.stat-mech↗

arXiv1998

Nonuniversality in short-time critical dynamics

We study behaviour of dynamical critical exponents of the two-dimensional Ising model with a line of defects. Simulations done at an early time (first 100 Monte Carlo steps) reveal that the critical exponent of Janssen et al (Z. Phys. B 73 539) depends on the strength of the exchange coupling constant (J') of the altered line. On the other hand, our simulations permit us to conclude that the dynamical critical exponent z is not sensitive to changes in J'. In adition, we investigate the possible invariance of the anomalous dimension of the magnetization at the beginning of the process.

cond-mat.stat-mech↗