Roughening phase transition in surface growth

We present first systematic numerical simulation results which show a strong indication of phase transitions, in both 2+1 and 3+1 dimensions, between weak-coupling and strong-coupling regimes in a surface-growth model. A modified ballistic deposition model is used to demonstrate the transitions and the roughness scaling exponent is measured. While the transition in 3+1 dimensions confirms the prediction of the renormalization-group analysis, the one in 2+1 dimensions had not been previously anticipated and exhibits a complex critical behavior.