Kinetics of the two-dimensional long-range Ising model at low temperatures

We study the low-temperature domain growth kinetics of the two-dimensional Ising model with long-range coupling J(r)~r^-(d+σ), where $d=2$ is the dimensionality. According to the Bray-Rutenberg predictions, the exponent σ controls the algebraic growth in time of the characteristic domain size L(t), L(t)~t1/z, with growth exponent z=1+σ for σ<1 and $z=2$ for σ>1. These results hold for quenches to a nonzero temperature $T>0$ below the critical temperature Tc. We show that, in the case of quenches to $T=0$, due to the long-range interactions, the interfaces experience a drift which makes the dynamics of the system peculiar. More precisely, we find that in this case the growth exponent takes the value $z=4/3$, independently of σ, showing that it is a universal quantity. We support our claim by means of extended Monte Carlo simulations and analytical arguments for single domains.