Enhanced Density Fluctuations Near a Disordered Chiral Topological Transition

Fuente: arXiv
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Main Authors: Ding, Hai-Tao, Mu, Sen, Kwek, Leong-Chuan, Lemarié, Gabriel, Gong, Jiangbin
Format: Preprint
Published: 2026
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author Ding, Hai-Tao
Mu, Sen
Kwek, Leong-Chuan
Lemarié, Gabriel
Gong, Jiangbin
author_facet Ding, Hai-Tao
Mu, Sen
Kwek, Leong-Chuan
Lemarié, Gabriel
Gong, Jiangbin
contents The universal statistics of density fluctuations of localized quantum states may offer unprecedented opportunities to probe and understand quantum transport in connection with dimensionality, coherence, symmetry and disorder. To date, the possible role of topological phase transitions in the fluctuation statistics is not studied yet. Using a Su-Schrieffer-Heeger chain subject to off-diagonal disorder (so that chiral symmetry is preserved), this work investigates how a disorder driven topological phase transition impacts on the spatial fluctuations of the logarithmic wave-packet density $\ln P(r)$ at distance $r$ from the initial excitation. Away from the transition, in both topological and trivial localized phases, the standard deviation follows the conventional one-dimensional scaling $σ[\ln P(r)]\sim r^θ$ with $θ\simeq 1/2$. Near the transition, however, the fluctuation growth is enhanced: the fitted exponent $θ$ increases above $1/2$ in a nonmonotonic manner before returning close to $1/2$ at criticality. We interpret this behavior from the energy-resolved density of states and localization length. Near the transition, several energy sectors carry appreciable spectral weight and exhibit competitive decay rates, preventing a single localization scale from dominating the accessible wave-packet tail and thereby enhancing the fluctuations of $\ln P(r)$. Our results establish wave-packet fluctuation statistics as a dynamical diagnostic of disordered chiral topological transitions and motivate broader studies of fluctuation phenomena in disordered topological quantum systems.
format Preprint
id arxiv_https___arxiv_org_abs_2605_29871
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Enhanced Density Fluctuations Near a Disordered Chiral Topological Transition
Ding, Hai-Tao
Mu, Sen
Kwek, Leong-Chuan
Lemarié, Gabriel
Gong, Jiangbin
Disordered Systems and Neural Networks
Quantum Physics
The universal statistics of density fluctuations of localized quantum states may offer unprecedented opportunities to probe and understand quantum transport in connection with dimensionality, coherence, symmetry and disorder. To date, the possible role of topological phase transitions in the fluctuation statistics is not studied yet. Using a Su-Schrieffer-Heeger chain subject to off-diagonal disorder (so that chiral symmetry is preserved), this work investigates how a disorder driven topological phase transition impacts on the spatial fluctuations of the logarithmic wave-packet density $\ln P(r)$ at distance $r$ from the initial excitation. Away from the transition, in both topological and trivial localized phases, the standard deviation follows the conventional one-dimensional scaling $σ[\ln P(r)]\sim r^θ$ with $θ\simeq 1/2$. Near the transition, however, the fluctuation growth is enhanced: the fitted exponent $θ$ increases above $1/2$ in a nonmonotonic manner before returning close to $1/2$ at criticality. We interpret this behavior from the energy-resolved density of states and localization length. Near the transition, several energy sectors carry appreciable spectral weight and exhibit competitive decay rates, preventing a single localization scale from dominating the accessible wave-packet tail and thereby enhancing the fluctuations of $\ln P(r)$. Our results establish wave-packet fluctuation statistics as a dynamical diagnostic of disordered chiral topological transitions and motivate broader studies of fluctuation phenomena in disordered topological quantum systems.
title Enhanced Density Fluctuations Near a Disordered Chiral Topological Transition
topic Disordered Systems and Neural Networks
Quantum Physics
url https://arxiv.org/abs/2605.29871