Electronic structure and local spectroscopy of 2-D Mott insulators

Abstract

Here we explore the electronic structure of Monolayer Sn/Si(111) √3 ×√3 which is thought to be a correlated 2D Mott insulator. Previous theoretical considerations have indicated that the system might display a row-wise AFM phase or a 1200 AFM Neel state.Utilizing DFT and DFT+U calculations we compare the various magnetic configurationsto identify the ground state configuration for the system which turns out to be in a row-wise AFM order. The mechanism behind the insulating behaviour can be attributed to be either a weak correlation driven Slater insulator or a true strongly correlated Mott insulator. We show that the system is most likely to be a Slater insulator from our calculations. By examining the core level electronic spectra we are also able to provide an explanation for the 2 double peaks seen in the core level ARPES spectra. Finally, we are able to observe a doping driven insulator to metal transition and calculate the electronic structure and magnetic configuration of these possible doped states.