Sticking coefficient for atoms incident upon metals within the exact factorization approach

The study of dynamical processes defines one of the busiest frontiers in theoretical Condensed-Matter Physics. The TDSE in the BO approximation has often been discussed in this context, but the combination of rapid nuclear motion under image-charge (IC) potentials with resonances defined by surface shake-ups renders the approximation inapplicable. We consider a model based on the Anderson-Newns to discuss the collision of a hydrogen atom with a metal and adopt the exact-factorization formalism [1], an approach that has been proven more reliable than the BO approximation, to compute the sticking coefficient as a function of incident energy. In our model, the metal occupies the half-space z<0, and the adatom impinges upon it along the z axis. The IC potential roughly splits the z>0 in two regions. For z>z_B, where z_B is a distance of a few Bohr radii, the adatom is neutral and the PES upon which the nucleus moves are flat. For z<z_B, the adatom being ionized, the PES are dominated by the IC potential, and the nuclear motion is accompanied by electron-hole excitations that dissipate energy and determine the probability of adsorption. We will present the results in the light of this description.

[1] A. Abedi, N. T. Maitra, and E. K. U. Gross, P.R.L, 105 123002 (2010)