Multiscale study of artificial quantum lattices formed on Cu(111) surfaces using CO molecules

Recent experiments have shown that carbon monoxide (CO) molecules deposited on Cu(111) surfaces serve as powerful platforms for probing topological quantum effects in artificial lattices. In this multiscale computational study, we integrate density functional theory (DFT) and density functional tight-binding (DFTB) to characterize the electronic properties of such systems.   Accurate DFT calculations of CO adsorption validate and calibrate our DFTB parameterizations. Leveraging DFTB, we then simulate extended lattices similar to those attained experimentally.  Quantum confinement of surface states emerging in honeycomb and Kagome-like lattices are systematically analyzed varying molecular spacing and adsorption registries.  Our results agree with recent experimental work on these systems and demonstrate that fine-tuning lattice parameters can markedly alter the electronic landscape and coherence properties of these artificial systems. These atomistic insights establish clear structure–property relationships and provide critical guidance for experimental efforts to develop robust, tunable CO-based platforms for quantum information sciences.