#### Abstract

We investigate the electronic correlation effects on the Sn/Si(111) $\sqrt{3}\times \sqrt{3}R{30}^{\xb0}$ 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 ${U}_{c}$ $~0.65$ 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 ${120}^{\xb0}$ AF one for certain interaction strengths is shown to be due to the longer-range single-particle hopping terms.

- Received 22 October 2010

DOI:https://doi.org/10.1103/PhysRevB.83.041104

© 2011 American Physical Society