Ferrimagnetic Slater Insulator Phase of the Sn/Ge(111) Surface

Abstract

We have performed the semilocal and hybrid density-functional theory (DFT) studies of the Sn/Ge(111) surface to identify the origin of the observed insulating $\sqrt{3}\times \sqrt{3}$ phase below $\sim$30 K. Contrasting with the semilocal DFT calculation predicting a metallic 3$\times$3 ground state, the hybrid DFT calculation including van der Waals interactions shows that the insulating ferrimagnetic structure with $\sqrt{3}\times \sqrt{3}$ structural symmetry is energetically favored over the metallic 3$\times$3 structure. It is revealed that the correction of self-interaction error with a hybrid exchange-correlation functional gives rise to a band-gap opening induced by a ferrimagnetic order. The results manifest that the observed insulating phase is attributed to the Slater mechanism via itinerant magnetic order rather than the hitherto accepted Mott-Hubbard mechanism via electron correlations.

4 figures, published in Phys. Rev. Lett

References in corpus (3)

• Long-range Coulomb interactions in surface systems: a first principles description within self-consistently combined GW and dynamical mean field theory
• Triangular Mott-Hubbard Insulator Phases of Sn/Si(111) and Sn/Ge(111) Surfaces
• Driving force of phase transition in Indium nanowires on Si(111)

Cited by in corpus (6)

• Spin-orbit coupling and magnetic interactions in Si(111):{C,Si,Sn,Pb}
• Chiral spin texture in the charge-density-wave phase of the correlated metallic Pb/Si(111) monolayer
• Antiferromagnetic Slater Insulator Phase of Na2IrO3
• Electronic correlation effects and Coulomb gap in the Si(111)-$(\sqrt{3}\times \sqrt{3})$-Sn surface
• Charge density wave in single-layer Pb/Ge(111) driven by Pb-substrate exchange interaction
• The electronic structure of a doped Mott-Hubbard surface