Enhanced Density Fluctuations Near a Disordered Chiral Topological Transition
Abstract
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)]∼ rθ with θ≃ 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.
Versions
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BibTeX
@misc{ding2026enhanced,
title = {{Enhanced Density Fluctuations Near a Disordered Chiral Topological Transition}},
author = {Hai-Tao Ding and Sen Mu and Leong-Chuan Kwek and Gabriel Lemarié and Jiangbin Gong},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.29871},
eprint = {2605.29871},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.29871},
}
RIS
TY - UNPB
TI - Enhanced Density Fluctuations Near a Disordered Chiral Topological Transition
AU - Hai-Tao Ding
AU - Sen Mu
AU - Leong-Chuan Kwek
AU - Gabriel Lemarié
AU - Jiangbin Gong
PY - 2026
DA - 2026/09/18
PB - arXiv
DO - 10.48550/arxiv.2605.29871
UR - https://arxiv.org/abs/2605.29871
AB - 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)]∼ r^θ with θ≃ 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.
SN - 2469-9950
SN - 2469-9969
ER -