title: Site determination and thermally assisted tunneling in homogenous nucleation.
abstract: A combined low-temperature scanning tunneling microscopy and density functional theory study on the binding and diffusion of copper monomers, dimers, and trimers adsorbed on Cu(111) is presented. Whereas atoms in trimers are found in fcc sites only, monomers as well as atoms in dimers can occupy the fcc as well as the metastable hcp site. In fact the dimer fcc-hcp configuration is only 1.3 meV less favorable with respect to the fcc-fcc configuration. This enables a confined intracell dimer motion, which at temperatures below 5 K is dominated by thermally assisted tunneling.
authors.affiliation: IBM Research, Zurich Research Laboratory, CH-8803 Rüschlikon, Switzerland.
authors.forename: Jascha
authors.initials: J
authors.lastname: Repp
authors.forename: Gerhard
authors.initials: G
authors.lastname: Meyer
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Rieder
authors.forename: Per
authors.initials: P
authors.lastname: Hyldgaard