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SiC(0001): a surface Mott-Hubbard insulator

V. I. Anisimov·A. E. Bedin·M. A. Korotin·G. Santoro·S. Scandolo·E. Tosatti
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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.

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V. I. Anisimov, A. E. Bedin, M. A. Korotin, G. Santoro, S. Scandolo, E. Tosatti. 1999-03-24. SiC(0001): a surface Mott-Hubbard insulator. https://doi.org/10.1103/physrevb.61.1752

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