Non-Hermitian butterfly spectra in a family of quasiperiodic lattices

Fuente: arXiv
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Main Authors: Wang, Li, Wang, Zhenbo, Chen, Shu
Format: Preprint
Published: 2024
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author Wang, Li
Wang, Zhenbo
Chen, Shu
author_facet Wang, Li
Wang, Zhenbo
Chen, Shu
contents We propose a family of exactly solvable quasiperiodic lattice models with analytical complex mobility edges, which can incorporate mosaic modulations as a straightforward generalization. By sweeping a potential tuning parameter $δ$, we demonstrate a kind of interesting butterfly-like spectra in complex energy plane, which depicts energy-dependent extended-localized transitions sharing a common exact non-Hermitian mobility edge. Applying Avila's global theory, we are able to analytically calculate the Lyapunov exponents and determine the mobility edges exactly. For the minimal model without mosaic modulation, a compactly analytic formula for the complex mobility edges is obtained, which, together with analytical estimation of the range of complex energy spectrum, gives the true mobility edge. The non-Hermitian mobility edge in complex energy plane is further verified by numerical calculations of fractal dimension and spatial distribution of wave functions. Tuning parameters of non-Hermitian potentials, we also investigate the variations of the non-Hermitian mobility edges and the corresponding butterfly spectra, which exhibit richness of spectrum structures.
format Preprint
id arxiv_https___arxiv_org_abs_2404_11020
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Non-Hermitian butterfly spectra in a family of quasiperiodic lattices
Wang, Li
Wang, Zhenbo
Chen, Shu
Disordered Systems and Neural Networks
We propose a family of exactly solvable quasiperiodic lattice models with analytical complex mobility edges, which can incorporate mosaic modulations as a straightforward generalization. By sweeping a potential tuning parameter $δ$, we demonstrate a kind of interesting butterfly-like spectra in complex energy plane, which depicts energy-dependent extended-localized transitions sharing a common exact non-Hermitian mobility edge. Applying Avila's global theory, we are able to analytically calculate the Lyapunov exponents and determine the mobility edges exactly. For the minimal model without mosaic modulation, a compactly analytic formula for the complex mobility edges is obtained, which, together with analytical estimation of the range of complex energy spectrum, gives the true mobility edge. The non-Hermitian mobility edge in complex energy plane is further verified by numerical calculations of fractal dimension and spatial distribution of wave functions. Tuning parameters of non-Hermitian potentials, we also investigate the variations of the non-Hermitian mobility edges and the corresponding butterfly spectra, which exhibit richness of spectrum structures.
title Non-Hermitian butterfly spectra in a family of quasiperiodic lattices
topic Disordered Systems and Neural Networks
url https://arxiv.org/abs/2404.11020