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Quantum ergodicity for periodic graphs

Mathematical Physics 2022-10-27 v2 math.MP Spectral Theory

Abstract

We prove quantum ergodicity for a family of periodic Schr\"odinger operators HH on periodic graphs. This means that most eigenfunctions of HH on large finite periodic graphs are equidistributed in some sense, hence delocalized. Our results cover the adjacency matrix on Zd\mathbb{Z}^d, the triangular lattice, the honeycomb lattice, Cartesian products and periodic Schr\"odinger operators on Zd\mathbb{Z}^d. The theorem applies more generally to any periodic Schr\"odinger operator satisfying an assumption on the Floquet eigenvalues.

Keywords

Cite

@article{arxiv.2208.12685,
  title  = {Quantum ergodicity for periodic graphs},
  author = {Theo Mckenzie and Mostafa Sabri},
  journal= {arXiv preprint arXiv:2208.12685},
  year   = {2022}
}

Comments

Two important updates. (1) Wencai Liu arXiv:2210.10532 has solved the open problem of v1, so quantum ergodicity holds for periodic operators on $\mathbb{Z}^d$ in all dimensions. (2) We now prove the Floquet assumption cannot be dropped and replaced by mere ac spectrum. More additions and stronger conclusions are featured. 26 pages, 5 figures

R2 v1 2026-06-25T02:00:29.061Z