The phase diagram of 2 interacting planar arrays of directed lines in random media was obtained by means of renormalization group analysis. The results were considered in terms of the roughening of anisotropically reconstructed crystal surfaces and the pinning of vortex line arrays in planar Josephson junctions. The observations included the stability of a flat anisotropically reconstructed surface, a novel second-order phase transition with continuously varying critical exponents, and the disappearance of the glassy so-called super-rough phases which had previously been found for a single line array.

J.Kierfeld, T.Hwa: Physical Review Letters, 1996, 77[20], 4233-6