{ "id": "1704.00932", "version": "v1", "published": "2017-04-04T09:36:36.000Z", "updated": "2017-04-04T09:36:36.000Z", "title": "Parseval frames of localized Wannier functions", "authors": [ "Horia D. Cornean", "Domenico Monaco" ], "comment": "18 pages", "categories": [ "math-ph", "cond-mat.mes-hall", "math.MP" ], "abstract": "Let $d \\le 3$ and consider a real analytic and $\\mathbb{Z}^d$-periodic family $\\{P(\\mathbf{k})\\}_{\\mathbf{k} \\in \\mathbb{R}^d}$ of orthogonal projections of rank $m$. A moving orthonormal basis of $\\mathrm{Ran}\\, P(\\mathbf{k})$ consisting of real analytic and $\\mathbb{Z}^d$-periodic Bloch vectors can be constructed if and only if the first Chern number(s) of $P$ vanish(es). Here we are mainly interested in the topologically obstructed case. First, by dropping the generating condition, we can construct a collection of $m-1$ orthonormal, real analytic, and $\\mathbb{Z}^d$-periodic Bloch vectors. Second, by dropping the orthonormality condition, we can construct a Parseval frame of $m+d-1$ real analytic and $\\mathbb{Z}^d$-periodic Bloch vectors which generate $\\mathrm{Ran}\\, P(\\mathbf{k})$. Both constructions are based on a two-step logarithm method which produces a moving orthonormal basis in the topologically trivial case. In applications to condensed matter systems, a moving Parseval frame of analytic, $\\mathbb{Z}^d$-periodic Bloch vectors generates a Parseval frame of exponentially localized composite Wannier functions for the occupied states of a gapped periodic Hamiltonian.", "revisions": [ { "version": "v1", "updated": "2017-04-04T09:36:36.000Z" } ], "analyses": { "subjects": [ "81Q30", "81Q70" ], "keywords": [ "parseval frame", "localized wannier functions", "real analytic", "moving orthonormal basis", "periodic bloch vectors generates" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable" } } }