posted on 2021-10-05, 21:05authored byG. Bracco, L. Vattuone, M. Smerieri, G. Carraro, L. Savio, G. Paolini, G. Benedek, P. M. Echenique, M. Rocca
The
current understanding of the dynamics of gas–surface
interactions is that all of the energy lost in the collision is transferred
to vibrations of the target. Electronic excitations were shown to
play a marginal role except for cases in which the impinging particles
have energies of several electronvolts. Here we show that this picture
does not hold for metal surfaces supporting acoustic surface plasmons.
Such loss, dressed with a vibronic structure, is shown to make up
a prominent energy transfer route down to the terahertz region for
Ne atoms scattering off Cu(111) and is expected to dominate for most
metals. This mechanism determines, e.g., the drag force acting on
telecommunication satellites, which are typically gold-plated to reduce
overheating by sunshine. The electronic excitations can be unambiguously
discerned from the vibrational ones under mild hyperthermal impact
conditions.