title: Ab initio study of the p-hole magnetism at polar surfaces of ZnO: the role of correlations.
abstract: A standard local density approximation and its self-interaction corrected version are applied to study spontaneous magnetization, promoted by localized p electron holes, of polar oxygen-terminated ZnO surfaces. The electronic properties and magnetic exchange interactions of three different facets are calculated. It is demonstrated that partially filled oxygen p orbitals of the polar surfaces exhibit magnetic moment formation and long range magnetic order leading to the occurrence of a ferromagnetic ground state. Monte Carlo simulations predict Curie temperatures above room temperature. In contrast to isolated defects in bulk materials, applying correlation corrections to the localized p-like surface states does not lead to a collapse of magnetic interaction: as the weakening of the magnetic interaction, caused by the reduced electronic overlap, is compensated by a strengthening due to an increase of the magnetic moments, the ferromagnetism can principally persist above room temperature, provided a large hole concentration exists.
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany.
authors.forename: Guntram
authors.initials: G
authors.lastname: Fischer
authors.forename: Nadiezhda
authors.initials: N
authors.lastname: Sanchez
authors.forename: Waheed
authors.initials: W
authors.lastname: Adeagbo
authors.forename: Zdzislawa
authors.initials: Z
authors.lastname: Szotek
authors.forename: Walter M
authors.initials: WM
authors.lastname: Temmerman
authors.forename: Arthur
authors.initials: A
authors.lastname: Ernst
authors.forename: Martin
authors.initials: M
authors.lastname: Hoffmann
authors.forename: Wolfram
authors.initials: W
authors.lastname: Hergert
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Muñoz