Localization Dynamics at the Exceptional Point of Non-Hermitian Creutz Ladder

We propose a quasi-one-dimensional non-Hermitian Creutz ladder with an entirely flat spectrum by introducing alternating gain and loss components while maintaining inversion symmetry. Destructive interference generates a flat spectrum at the exceptional point, where the Creutz ladder maintains coale...

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Bibliographic Details
Published inChinese physics letters Vol. 41; no. 2; pp. 27201 - 27207
Main Authors Zhang, S. M., He, T. Y., Jin, L.
Format Journal Article
LanguageEnglish
Published Chinese Physical Society and IOP Publishing Ltd 01.02.2024
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Summary:We propose a quasi-one-dimensional non-Hermitian Creutz ladder with an entirely flat spectrum by introducing alternating gain and loss components while maintaining inversion symmetry. Destructive interference generates a flat spectrum at the exceptional point, where the Creutz ladder maintains coalesced and degenerate eigenvalues with compact localized states distributed in a single plaquette. All excitations are completely confined within the localization area, unaffected by gain and loss. Single-site excitations exhibit nonunitary dynamics with intensities increasing due to level coalescence, while multiple-site excitations may display oscillating or constant intensities at the exceptional point. These results provide insights into the fascinating dynamics of non-Hermitian localization, where level coalescence and degeneracy coexist at the exceptional point.
ISSN:0256-307X
1741-3540
DOI:10.1088/0256-307X/41/2/027201