RENORMALIZATION-GROUP STUDY OF A DRIVEN CONTINUUM MODEL FOR MOLECULAR-BEAM EPITAXY

We use the dynamic renormalization group technique to study a continuu m model for molecular beam epitaxy for both one- and two-dimensional s ubstrates. Relaxation of the growing film is due to surface tension an d surface diffusion. In 1 + 1 dimensions we find a purely diffusive st rong-coupling fixed point with a dynamic exponent z different from tha t given by the linear theory as well as the Edwards-Wilkinson fixed po int and a fixed point corresponding to unstable growth. In 2 + 1 dimen sions the purely diffusive fixed point is absent at the one loop order but the other two fixed points are still present.