12 October 2000, 2 p.m.

Dr. Jouni Kallunki
(University of Essen)
Nonlinear step evolution on vicinal surfaces during MBE

Abstract:
In 1990 Bales and Zangwill showed that straight steps on a surface are unstable against collective meandering when the crystal is growing. Since then the phenomenon has been observed in several simulations and experiments. However, the first quantitative results on the meander wavelength, published last year, showed a discrepancy between theory and experiments. An equation describing the evolution of the in-phase meander of an array of steps has been derived from the BCF-theory of crystal growth. This makes it possible to follow the step evolution far into the nonlinear regime. Results of this approach will be presented and the comparison with the recent experiments are made.