Static and dynamic length scales in a simple glassy plaquette model.

We study static and dynamic spatial correlations in a two-dimensional spin model with four-body plaquette interactions and standard Glauber dynamics by means of analytic arguments and Monte Carlo simulations. We study in detail the dynamical behavior which becomes glassy at low temperatures, due to the emergence of effective kinetic constraints in a dual representation where spins are mapped to plaquette variables. We study the interplay between nontrivial static correlations of the spins and the dynamic "four-point" correlations usually studied in the context of supercooled liquids. We show that slow dynamics is spatially heterogeneous due to the presence of diverging length scales and scaling, as is also found in kinetically constrained models. This analogy is illustrated by a comparative study of a froth model where the kinetic constraints are imposed.