Correlation induced charge ordering metal-insulator transition in a two-dimensional triangular lattice (original) (raw)

Low dimensional systems are characterized by at least one spatial dimension of only some atoms. Such size reduction has often important consequences for physical properties. Electronic correlation and electron-phonon coupling can originate Mott insulators or charge density waves (CDWs), both phenomena enhanced by dimensionality reduction. Interfaces offer a natural way of reducing the dimensionality. Among all the surfaces, semiconducting surfaces are particularly well adapted for electronic correlation studies. In them, correlation is enhanced because of the low dimension, the electronic localization in dangling bonds and the large inter-orbital distances in reconstructions. Despite these factors favoring correlation, eventually stronger than in bulk systems, the field is by far much less developed. We review here the discovery of correlated Phys. Status Solidi A 209, No. 4, 614-626 (2012) /