On topological obstructions to the existence of non-periodic Wannier bases

Fuente: arXiv
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Main Authors: Kordyukov, Yu., Manuilov, V.
Format: Preprint
Published: 2023
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author Kordyukov, Yu.
Manuilov, V.
author_facet Kordyukov, Yu.
Manuilov, V.
contents Recently, M. Ludewig and G. C. Thiang introduced a notion of a uniformly localized Wannier basis with localization centers in an arbitrary uniformly discrete subset $D$ in a complete Riemannian manifold $X$. They show that, under certain geometric conditions on $X$, the class of the orthogonal projection onto the span of such a Wannier basis in the $K$-theory of the Roe algebra $C^*(X)$ is trivial. In this paper, we clarify the geometric conditions on $X$, which guarantee triviality of the $K$-theory class of any Wannier projection. We show that this property is equivalent to triviality of the unit of the uniform Roe algebra of $D$ in the $K$-theory of its Roe algebra, and provide a geometric criterion for that. As a consequence, we prove triviality of the $K$-theory class of any Wannier projection on a connected proper measure space $X$ of bounded geometry with a uniformly discrete set of localization centers.
format Preprint
id arxiv_https___arxiv_org_abs_2304_00125
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle On topological obstructions to the existence of non-periodic Wannier bases
Kordyukov, Yu.
Manuilov, V.
Operator Algebras
Mathematical Physics
Metric Geometry
Recently, M. Ludewig and G. C. Thiang introduced a notion of a uniformly localized Wannier basis with localization centers in an arbitrary uniformly discrete subset $D$ in a complete Riemannian manifold $X$. They show that, under certain geometric conditions on $X$, the class of the orthogonal projection onto the span of such a Wannier basis in the $K$-theory of the Roe algebra $C^*(X)$ is trivial. In this paper, we clarify the geometric conditions on $X$, which guarantee triviality of the $K$-theory class of any Wannier projection. We show that this property is equivalent to triviality of the unit of the uniform Roe algebra of $D$ in the $K$-theory of its Roe algebra, and provide a geometric criterion for that. As a consequence, we prove triviality of the $K$-theory class of any Wannier projection on a connected proper measure space $X$ of bounded geometry with a uniformly discrete set of localization centers.
title On topological obstructions to the existence of non-periodic Wannier bases
topic Operator Algebras
Mathematical Physics
Metric Geometry
url https://arxiv.org/abs/2304.00125