On the classical behavior, coherent and incoherent contributions to scattering of atoms from a surface

Abstract

In this work we calculate the coherent and incoherent contributions to the diffraction probability of atoms scattered by a surface. We are interested in exploring the relative importance of each of these contributions, and compare them with results obtained from molecular dynamics calculations. To achieve this goal, we employed a method developed by Heller that consists of writing the incident plane wave as a sum of Gaussian wave packets, propagating them independently by using the time dependent Schrödinger equation, and constructing the scattered wave function by adding coherently the scattered packets. For the system studied, the molecular dynamics results show the largest intensity in the specular region and also display a classical rainbow structure. On the other hand, the quantum results exhibit diffraction features, with the coherent contribution accounting for most of the total intensity probability.