title: Adatom-adatom interaction mediated by an underlying surface phase transition.
abstract: Low temperature scanning tunneling microscopy measurements on the adsorption of single Pb adatoms on Si(111)-(square root 3 x square root 3)-Pb surfaces reveal the vertical displacement patterns induced on the substrate by these Pb adatoms as well as a novel adatom-adatom interaction. The origin of both can be traced back to the (square root 3 x square root 3)<-->(3 x 3) phase transition taking place at lower temperatures. A Landau-like approach explains the displacement patterns as due to the corresponding order parameter and shows that the vicinity of a surface phase transition gives rise to a nonmonotonic adatom-adatom interaction.
authors.affiliation: Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Brihuega
authors.forename: A
authors.initials: A
authors.lastname: Cano
authors.forename: M M
authors.initials: MM
authors.lastname: Ugeda
authors.forename: J J
authors.initials: JJ
authors.lastname: Sáenz
authors.forename: A P
authors.initials: AP
authors.lastname: Levanyuk
authors.forename: J M
authors.initials: JM
authors.lastname: Gómez-Rodríguez