2009/06/25 by Simone Selenu, Selenu, Simone
Physics and Astronomy · #FOS: Physical sciences #Force Microscopy Techniques and Applications #Materials Science (cond-mat.mtrl-sci) #Mechanical and Optical Resonators #Other Condensed Matter (cond-mat.other) #Quantum and electron transport phenomena #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.48550/arxiv.0906.4670
arxiv created 2009/06/25 · openalex publication_date 2009/06/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It is nowadays a quite diffuse idea that variations of polarisation in condensed matter theory are related to a "Berry phase". The derivation of the latter geometric phase is correct \itonly if the restrictive periodic gauge\citeKS-V is used for its derivation, aside giving rise to a "quantum of polarisation" that is of difficult theoretical interpretation. Its derivation has not been demonstrated in the general case of an external homogeneous electric field interacting with the electronic field. In the present paper we give a brief derivation of the polarisation differences in a general manner than in\citeKS-V allowing for a general boundary conditions freedom showing that is possible to define it even in the presence of an external electric field interacting with the electronic field and writing equations in a way directly implementable in modern first principles codes.