Substrate-mediated, long-range oscillatory interaction between adatoms: Cu/Cu(111)

Phys. Rev. Lett. 85, 2981 (2000)

J. Repp¹, F. Moresco¹, G. Meyer^1,2, K.-H. Rieder¹,
^[1}Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
^{2}Paul Drude Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin, Germany

P. Hyldgaard, and M. Persson,
Department of Applied Physics, Chalmers/Göteborg University, S-412 96 Göteborg, Sweden

Abstract

A quantitative study of the long-range interaction between single copper adatoms on Cu(111) mediated by the electrons in the two-dimensional surface state band is presented. The interaction potential was determined by evaluating the distance distribution of two adatoms from a series of STM images taken at temperatures of 9-21K. The long-range interaction is oscillatory with a period of half the Fermi wavelength and decays for larger distances d as 1/d². Five potential minima were identified for separations of up to 70Å. The interaction significantly changes the growth of Cu/Cu(111) at low temperatures.

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