Wannier-Based Definition of Layer Polarizations in Perovskite Superlattices

Xifan Wu, Oswaldo Diéguez, Karin M. Rabe, David Vanderbilt
2006 Physical Review Letters  
In insulators, the method of Marzari and Vanderbilt [Phys. Rev. B {\bf 56}, 12847 (1997)] can be used to generate maximally localized Wannier functions whose centers are related to the electronic polarization. In the case of layered insulators, this approach can be adapted to provide a natural definition of the local polarization associated with each layer, based on the locations of the nuclear charges and one-dimensional Wannier centers comprising each layer. Here, we use this approach to
more » ... is approach to compute and analyze layer polarizations of ferroelectric perovskite superlattices, including changes in layer polarizations induced by sublattice displacements (i.e., layer-decomposed Born effective charges) and local symmetry breaking at the interfaces. The method provides a powerful tool for analyzing the polarization-related properties of complex layered oxide systems.
doi:10.1103/physrevlett.97.107602 pmid:17025854 fatcat:3chech7nonevhn6dofmgzapfwa