Constructing optimal Wannier functions via potential theory: isolated single band for matrix models

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteur principal: Zhang, Hanwen
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866913805255049216
author Zhang, Hanwen
author_facet Zhang, Hanwen
contents We present a rapidly convergent scheme for computing globally optimal Wannier functions of isolated single bands for matrix models in two dimensions. The scheme proceeds first by constructing provably exponentially localized Wannier functions directly from parallel transport (with simple analytically computable corrections) when topological obstructions are absent. We prove that the corresponding Wannier functions are real when the matrix model possesses time-reversal symmetry. When a band has a nonzero Berry curvature, the resulting Wannier function is not optimal, but it is transformed into the global optimum by a single gauge transformation that eliminates the divergence of the Berry connection. Complete analysis of the construction is presented, paving the way for further improvements and generalizations. The performance of the scheme is illustrated with several numerical examples.
format Preprint
id arxiv_https___arxiv_org_abs_2502_08641
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Constructing optimal Wannier functions via potential theory: isolated single band for matrix models
Zhang, Hanwen
Mathematical Physics
Numerical Analysis
Computational Physics
We present a rapidly convergent scheme for computing globally optimal Wannier functions of isolated single bands for matrix models in two dimensions. The scheme proceeds first by constructing provably exponentially localized Wannier functions directly from parallel transport (with simple analytically computable corrections) when topological obstructions are absent. We prove that the corresponding Wannier functions are real when the matrix model possesses time-reversal symmetry. When a band has a nonzero Berry curvature, the resulting Wannier function is not optimal, but it is transformed into the global optimum by a single gauge transformation that eliminates the divergence of the Berry connection. Complete analysis of the construction is presented, paving the way for further improvements and generalizations. The performance of the scheme is illustrated with several numerical examples.
title Constructing optimal Wannier functions via potential theory: isolated single band for matrix models
topic Mathematical Physics
Numerical Analysis
Computational Physics
url https://arxiv.org/abs/2502.08641