Long-range Coulomb interactions in surface systems: a first principles description within self-consistently combined GW and dynamical mean field theory

TL;DR

This paper develops a first-principles method combining GW and DMFT to accurately describe long-range Coulomb interactions in surface adatom systems, explaining their spectral properties and phase tendencies.

Contribution

It introduces a fully ab initio approach to derive and solve low-energy Hamiltonians for surface adatom systems using self-consistent GW+DMFT, capturing long-range interactions.

Findings

Calculated spectra match experimental photoemission data.

Long-range interactions explain the transition from Mott to charge-ordered states.

The method provides insights into the complex interplay of spin and charge in surface systems.

Abstract

Systems of adatoms on semiconductor surfaces display competing ground states and exotic spectral properties typical of two-dimensional correlated electron materials which are dominated by a complex interplay of spin and charge degrees of freedom. We report a fully ab initio derivation of low energy Hamiltonians for the adatom systems Si(111):X, with X=Sn, Si, C, Pb, that we solve within self-consistent combined GW and dynamical mean field theory ("GW+DMFT"). Calculated photoemission spectra are in agreement with available experimental data. We rationalize experimentally observed tendencies from Mott physics towards charge-ordering along the series as resulting from substantial long-range interactions.