Work

Don't mind the gap: Absolutely Continuous Edge Spectrum in a Mobility Gap

Year: 2026
Type: preprint
Abstract: We study the edge spectrum of two-dimensional lattice Hamiltonians and magnetic Schrödinger operators in a mobility gap, an energy interval in which the bulk spectrum is potentially localized rather than necessarily absent. Under suitable localization and boundary assumptions, we prove that a constant nonzero bulk topological index implies that the entire interval belongs to the absolutely continuous spectrum of the corresponding half-space operator. The absolutely continuous spectral multiplicity is bounded below by the absolute value of the index at almost every energy in the interval. The first version of the auxiliary-space cut construction in Section 2.3 was generated using ChatGPT 6.
Language: English
Open Access status: green
OpenAlex ID: W7214044359
Cites: 11
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Related to: 10