Unveiling new systematics in the self-assembly of atomic chains on Si(111)
Battaglia, Corsin; Cercellier, Hervé; Monney, Claude; Despont, Laurent; Garnier, Michael Gunnar; Aebi, Philipp Switzerland
Self-assembled atomic chains on Si(111) represent a fascinating family of nanostructures with quasi-one-dimensional electronic properties. These surface reconstructions are stabilized by a variety of adsorbates ranging from alkali and alkaline earth metals to noble and rare earth metals. Combining the complementary strength of dynamical low-energy electron diffraction, scanning tunneling microscopy and angle-resolved photoemission spectroscopy, we show that besides monovalent and divalent adsorbates, trivalent adsorbates are also able to stabilize silicon honeycomb chains. Consequently silicon honeycomb chains emerge as a most stable, universal building block shared by many atomic chain structures. We
further relate the valence state of the adsorbate to the accessible symmetries of the chains and discuss the role of silicon adatoms in compensating local charge defects.