title: Structure and spectroscopy of surface defects from scanning force microscopy: theoretical predictions
abstract: A possibility to study surface defects by combining noncontact scanning force microscopy (SFM) imaging with atomically resolved optical spectroscopy is demonstrated by modeling an impurity Cr3+ ion at the MgO(001) surface with a SFM tip. Using a combination of the atomistic simulation and the ab initio electronic structure calculations, we predict a topographic noncontact SFM image of the defect and show that its optical transitions can be either enhanced or suppressed depending on the tip atomistic structure and its position relative to the defect. These effects should allow identification of certain impurity species through competition between radiative and nonradiative transitions.
authors.affiliation: Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors.initials: LN
authors.lastname: Kantorovich
authors.initials: AL
authors.lastname: Shluger
authors.initials: AM
authors.lastname: Stoneham