A NEW UNIVERSALITY CLASS FOR KINETIC GROWTH - ONE-DIMENSIONAL MOLECULAR-BEAM EPITAXY

We study a new model for kinetic growth motivated by the physics of molecular-beam epitaxy where the deposited atoms can relax to kink sites maximizing the number of saturated bonds. The model is thus intermediate between the well-known random-deposition model with no relaxation and the random-deposition model with perfect relaxation, producing growth exponents which are in between these two extremes. In particular, the growth exponent beta, defining the interface width W approximately t-beta at intermediate times, is found to be beta almost-equal-to 0.375 +/- 0.005 in d = 1+ 1 dimensions. Our estimated alpha for this model is around 1.5 for 1 + 1 dimensions.