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SYWS: Simulation von Wachstum und Strukturbildung

SYWS 1: Fachsitzung I

SYWS 1.2: Fachvortrag

Thursday, March 29, 2001, 15:30–15:45, S12

Adatom-Density Kinetic-Monte Carlo (AD-KMC): a new method for fast growth simulation — •Lorenzo Mandreoli and Jörg Neugebauer — Fritz-Haber-Insitut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin

Growth simulations are normally performed using two main approaches: Kinetic-Monte Carlo (KMC) (working on an atomistic scale, thus allowing a direct use of microscopic parameters) and contiunuum equations (working on a mesoscopic scale, thus relaying on effective/empirical parameters). Generally, KMC methods are numerically much slower than continuum equations. We have developed a new method which combines the advantages of both methods. The main idea is to directly calculate the time evolution of the adatom density, rather than following the trajectory of each individual adatom as for the KMC. The adatom density is obtained by solving a generalized diffusion equation and taking all microscopic processes into account. In this way most of the computer time is spent on describing growth events (island nucleation, attachment at steps) rather than on elementary diffusion events making this method very fast. To test the method, we have compared the results with conventional KMC-techniques and considered various examples (island nucleation, 2D- vs. 3D- growth, self-organization in V-grooves, lateral overgrowth).