A new universality class for kinetic growth: One-dimensional molecular-beam epitaxy

Abstract

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 \ensuremath{\beta}, defining the interface width W\ensuremath{\sim}${\mathit{t}}^{\mathrm{\ensuremath{\beta}}}$ at intermediate times, is found to be \ensuremath{\beta}\ensuremath{\approxeq}0.375\ifmmode\pm\else\textpm\fi{}0.005 in d=1+1 dimensions. Our estimated \ensuremath{\alpha} for this model is around 1.5 for 1+1 dimensions.