Luís A. Nunes Amaral

co-Director, Northwestern Institute on Complex Systems
Professor of Chemical & Biological Engineering
Professor of Physics & Astronomy (by courtesy)
Professor of Medicine (by courtesy)

Chemical & Biological Engineering
2145 Sheridan Road (Room E136)
EvanstonIL 60208US
Phone: (847) 491-7850


We introduce two models for the action of impurities in epitaxial growth. In the first, the interaction between the diffusing adatoms and the impurities is ''barrierlike'' and, in the second, it is ''traplike.'' For the barrier model, we find a symmetry-breaking effect that leads to an overall downhill current. As expected, such a current produces Edwards-Wilkinson scaling. For the trap model, no symmetry breaking occurs and the scaling behavior appears to be of the conserved Kardar-Parisi-Zhang type.