Physics Department presents a Condensed Matter Theory Seminar
Condensed Matter Theory:
"Sticking coefficent for atoms incident upon metals within the exact factorization"
Dr. Celso Ricardo Caldeira Rego
Max Planck Institute of Microstructure Physics, Halle Germany
The complete understanding of dynamical processes arising when an atom approaches a metallic surface is a challenge at the core of Quantum Mechanics. To date, the most common approach to tackle this problem is the Born Oppenheimer approximation, which is, nonetheless inapplicable when one considers non-adiabatic contributions resulting from the rapid nuclear motion under image-charge (IC) potentials. Here, we propose to rely on the Exact Factorization formalism to investigate the role of non-adiabatic electron-hole excitations in dynamical quantum processes. We consider the Anderson-Newns Hamiltonian to model the collision of a hydrogen atom with metal and study 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. We observe that the IC potential roughly splits the z>0 into two regions. For z>zB, where Bz is a distance of a few Bohr radii, the adatom is neutral and the PES upon which the nucleus moves are flat. For z<zB, 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 light of this description
Friday, March 15 at 1:00pm to 2:30pm
Dana Research Center, 114 110 Forsyth St