SiC(0001): a surface Mott-Hubbard insulator

Abstract

We present ab-initio electronic structure calculations for the Si-terminated SiC(0001)$\sqrt{3}\times \sqrt{3}$ surface. While local density approximation (LDA) calculations predict a metallic ground state with a half-filled narrow band, Coulomb effects, included by the spin-polarized LDA+U method, result in a magnetic (Mott-Hubbard) insulator with a gap of 1.5 eV, comparable with the experimental value of 2.0 eV. The calculated value of the inter-site exchange parameter, J=30K, leads to the prediction of a paramagnetic Mott state, except at very low temperatures. The observed Si 2p surface core level doublet can naturally be explained as an on-site exchange splitting.

RevTex, 4 pages, 4 eps-figures

References in corpus (3)

• Long range Neel order in the triangular Heisenberg model
• Charge density waves and surface Mott insulators for adlayer structures on semiconductors: extended Hubbard modeling
• Metallic charge density waves and surface Mott insulators for adlayer structures on semiconductors: extended Hubbard modeling

Cited by in corpus (7)

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• Triangular Mott-Hubbard Insulator Phases of Sn/Si(111) and Sn/Ge(111) Surfaces
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• Exchange coupling in semiconductor nanostructures: Validity and limitations of the Heitler-London approach
• Reliability of the Heitler-London approach for the exchange coupling between electrons in semiconductor nanostructures
• Spectral Function in Mott Insulating Surfaces
• Spectroscopic fingerprints of a surface Mott-Hubbard insulator: the case of SiC(0001)