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Observation of a Mott insulating ground state for Sn/Ge(111) at low temperature

R. Cortes·A. Tejeda·J. Lobo·C. Didiot·B. Kierren·D. Malterre·E. G. Michel·A. Mascaraque
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Abstract

We report an investigation on the properties of 0.33 ML of Sn on Ge(111) at temperatures down to 5 K. Low-energy electron diffraction and scanning tunneling microscopy show that the (3x3) phase formed at 200 K, reverts to a new (root-3xroot-3)R30 phase below 30 K. The vertical distortion characteristic of the (3x3) phase is lost across the phase transition. Angle-resolved photoemission experiments show that concomitantly with the structural phase transition, a metal-insulator phase transition takes place. In agreement with theoretical predictions, the (root-3xroot-3)R30 ground state is interpreted as the experimental realization of a Mott insulator for a narrow half-filled band in a two-dimensional triangular lattice.

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R. Cortes, A. Tejeda, J. Lobo, C. Didiot, B. Kierren, D. Malterre, E. G. Michel, A. Mascaraque. 2006-01-02. Observation of a Mott insulating ground state for Sn/Ge(111) at low temperature. https://doi.org/10.1103/physrevlett.96.126103

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