Dynamics and steady states of tight-binding chains in presence of isolated defects

Fuente: arXiv
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Main Authors: Acharya, Anish, Giuggioli, Luca, Gupta, Shamik
Format: Preprint
Published: 2025
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author Acharya, Anish
Giuggioli, Luca
Gupta, Shamik
author_facet Acharya, Anish
Giuggioli, Luca
Gupta, Shamik
contents Reduced transport and localization in isolated quantum systems are typically attributed to spatially-extended disorder, but may also emerge from the influence of a few controllable defects. We show here how a single defect profoundly reshapes wave-function spreading on a finite and periodic tight-binding lattice. Adapting the defect technique from classical random-walk studies, we obtain exact time-resolved site-occupation probabilities and several observables of interest. Even a single defect induces remarkable nonlinear effects, including non-monotonic suppression of transport, enhanced localization at distant sites, and strong sensitivity to the initial particle position at long times. These results demonstrate that minimal perturbations can generate nontrivial long-time transport signatures, giving rise to a microscopic defect-driven mechanism of quantum localization. Although the main results presented pertain to a single isolated defect, we show that the developed formalism may naturally extend to multiple as well as to a wider class of defects.
format Preprint
id arxiv_https___arxiv_org_abs_2512_15130
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Dynamics and steady states of tight-binding chains in presence of isolated defects
Acharya, Anish
Giuggioli, Luca
Gupta, Shamik
Quantum Physics
Statistical Mechanics
Reduced transport and localization in isolated quantum systems are typically attributed to spatially-extended disorder, but may also emerge from the influence of a few controllable defects. We show here how a single defect profoundly reshapes wave-function spreading on a finite and periodic tight-binding lattice. Adapting the defect technique from classical random-walk studies, we obtain exact time-resolved site-occupation probabilities and several observables of interest. Even a single defect induces remarkable nonlinear effects, including non-monotonic suppression of transport, enhanced localization at distant sites, and strong sensitivity to the initial particle position at long times. These results demonstrate that minimal perturbations can generate nontrivial long-time transport signatures, giving rise to a microscopic defect-driven mechanism of quantum localization. Although the main results presented pertain to a single isolated defect, we show that the developed formalism may naturally extend to multiple as well as to a wider class of defects.
title Dynamics and steady states of tight-binding chains in presence of isolated defects
topic Quantum Physics
Statistical Mechanics
url https://arxiv.org/abs/2512.15130