Nondemolition filtering of an embedded cluster-state scar under continuous local monitoring
Abstract
Identifying a low-entanglement eigenstate inside a many-body spectrum and preserving it during measurement are distinct tasks. We construct an explicit local ring Hamiltonian with an exact cluster-state eigenvector and study continuous monitoring of its stabilizer defects. For arbitrary mixed inputs, the conditional cluster fidelity is the initial target weight divided by the no-observed-click probability. A positive defect-operator gap gives finite-time bounds that hold for noncommuting Hamiltonian dynamics, nonnormal effective generators and imperfect detection. At fixed total monitoring rate, the guaranteed exponent falls inversely with system size; high conditional fidelity does not remove the preparation cost set by the initial overlap. Exact diagonalization up to eleven qubits gives finite-size evidence for a cluster-state outlier in a chaotic spectral background. Independent matrix and trajectory calculations verify the dynamics and a conservative coherent-error bound. This construction specializes established scar embedding and nondemolition verification frameworks, with explicit measurement assumptions, finite-time guarantees and resource limitations.
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BibTeX
@misc{wang2026nondemolition,
title = {{Nondemolition filtering of an embedded cluster-state scar under continuous local monitoring}},
author = {Ximo Wang and Xi Zhao and Xiayu Sun and Qiwei Han and Yuhang Wang and Chunxiao Du and Wenxiu Li and Hao Zhang and Rui Li},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.24166},
eprint = {2609.24166},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.24166},
}
RIS
TY - UNPB
TI - Nondemolition filtering of an embedded cluster-state scar under continuous local monitoring
AU - Ximo Wang
AU - Xi Zhao
AU - Xiayu Sun
AU - Qiwei Han
AU - Yuhang Wang
AU - Chunxiao Du
AU - Wenxiu Li
AU - Hao Zhang
AU - Rui Li
PY - 2026
DA - 2026/09/21
PB - arXiv
DO - 10.48550/arxiv.2609.24166
UR - https://arxiv.org/abs/2609.24166
AB - Identifying a low-entanglement eigenstate inside a many-body spectrum and preserving it during measurement are distinct tasks. We construct an explicit local ring Hamiltonian with an exact cluster-state eigenvector and study continuous monitoring of its stabilizer defects. For arbitrary mixed inputs, the conditional cluster fidelity is the initial target weight divided by the no-observed-click probability. A positive defect-operator gap gives finite-time bounds that hold for noncommuting Hamiltonian dynamics, nonnormal effective generators and imperfect detection. At fixed total monitoring rate, the guaranteed exponent falls inversely with system size; high conditional fidelity does not remove the preparation cost set by the initial overlap. Exact diagonalization up to eleven qubits gives finite-size evidence for a cluster-state outlier in a chaotic spectral background. Independent matrix and trajectory calculations verify the dynamics and a conservative coherent-error bound. This construction specializes established scar embedding and nondemolition verification frameworks, with explicit measurement assumptions, finite-time guarantees and resource limitations.
ER -