title: Understanding the insulating nature of alkali-metal/Si(111):B interfaces.
abstract: We have recently revisited the phase diagram of alkali-metal/Si(111):B semiconducting interfaces previously suggested as the possible realization of a Mott-Hubbard insulator on a triangular lattice. The insulating character of the 2√[3] × 2√[3]R30 surface reconstruction observed at the saturation coverage, i.e. 0.5 ML, has been shown to find its origin in a giant alkali-metal-induced vertical distortion. Low energy electron diffraction, photoemission spectroscopy and scanning tunneling microscopy and spectroscopy experiments coupled with linear augmented plane-wave density functional theory calculations allow a full understanding of the k-resolved band structure, explaining both the inhomogeneous charge transfers into an Si-B hybridized surface state and the opening of a band gap larger than 1 eV. Moreover, √[3] × √[3]R30, 3 × 3 and 2√[3] × 2√[3]R30 surface reconstructions observed as a function of coverage may reveal a filling-controlled transition from a half-filled correlated magnetic material to a strongly distorted band insulator at saturation.
authors: Institut Jean Lamour UMR 7198, Université de Lorraine/CNRS, B.P. 70239 F-54506 Vandœuvre-lès-Nancy, France. yannick.fagot@univ-lorraine.fr
authors: Y
authors: Y
authors: Fagot-Revurat
authors: C
authors: C
authors: Tournier-Colletta
authors: L
authors: L
authors: Chaput
authors: A
authors: A
authors: Tejeda
authors: L
authors: L
authors: Cardenas
authors: B
authors: B
authors: Kierren
authors: D
authors: D
authors: Malterre
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authors: Le Fèvre
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authors: Bertran
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authors: Taleb-Ibrahimi