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

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