Critical behaviour of driven bilayer systems: a field-theoretic renormalization group study

We investigate the static and dynamic critical behaviour of a uniformly dri ven bilayer Ising lattice gas at half-filling. Depending on the strength of the interlayer coupling J, phase separation occurs across or within the tw o layers. The former transitions are controlled by the universality class o f model A (corresponding to an Ising, model with Glauber dynamics), with up per critical dimension d(c) = 4. The latter transitions are dominated by th e universality class of the standard (single-layer) driven Ising lattice ga s, with d(c) = 5 and a nonclassical anisotropy exponent. These two distinct critical lines meet at a nonequilibrium bicritical point which also falls into the driven Ising class. At all transitions, novel couplings and danger ous irrelevant operators determine corrections to scaling.