Effect of laser on migration of surface adatoms: high friction limit

We obtain a microscopic lattice-dynamic Hamiltonian of a system interacting with laser based on the electronic system-specific-time-dependent Schroedinger equation and the system-specific time laser theory. From this Hamiltonian, we use the Mori formalism to develop a coupled set of equations for various physical correlation functions and obtain the inverse friction expression of the velocity-velocity self- correlation function in the high-friction limit. An analytical formula is obtained for the diffusion constant of a particle diffusion in a periodic background. The analysis of the formula shows that the effect of non-resonance interaction of laser on the migration of surface adatoms is so small that it can be ignored for ordinary-intensity laser. In other words, only resonance interaction of laser affects the migration of surface adatoms at low temperature. Our results well agree with the qualitative experiment results of laser induced epitaxy.