Macroscopic electrical polarization of materials (disordered and crystalline)

Abstract

I provide here a comprehensive presentation of the so called ‘modern theory of polarization’, based on a Berry phase. This theory is implemented as a standard option in most electronic-structure codes for both crystalline and noncrystalline materials, and is routinely used whenever features ot the macroscopic electrical polarization of materials are addressed. Several reviews of the modern theory exist in the literature; with respect to them, the present work has important elements of novelty. In this work I present a formal derivation, starting from the many-body wavefunction at the most general level, and eventually specialising to the case of single-determinant wavefunctions for either disordered or crystalline materials.