We investigate the electronic correlation effects on the Sn/Si(111) surface by combining the ab initio density-functional approach with the dynamical mean-field theory, the variational cluster approach, and the dual fermion (DF) method. A metal-insulator transition with first or second order at finite or zero temperature is predicted at a critical on-site Hubbard eV and the system is proven to be short-range correlated. The electron-electron interaction favors a row-wise antiferromagnetic (RW-AFM) order, although the noninteracting system does not have a pronounced nesting at the Fermi surface. The stabilization of the RW-AFM order over the AF one for certain interaction strengths is shown to be due to the longer-range single-particle hopping terms.
- Received 22 October 2010
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