Abstract
Motivated by recent simulation results of the suppression of interfacial roughening, the authors study analytically the interfaces in non-equilibrium steady states for systems with bulk conservation. The general method of deriving interfacial properties from the bulk is developed, and the necessity of employing the full dynamics, even for static properties, is exhibited. Applying this to the randomly driven diffusion system, they obtained novel results. Specifically, height-height correlation diverges weakly as 1/q for small wavevector q, thus displaying the first analytical evidence of roughening suppression for driven systems.