Ab initio study of the p-hole magnetism at polar surfaces of ZnO: the role of correlations.

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.