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Bibliographic Details
Main Authors: Kiely, Anthony, Landi, Gabriel T.
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2507.06303
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author Kiely, Anthony
Landi, Gabriel T.
author_facet Kiely, Anthony
Landi, Gabriel T.
contents The joint state of a continuously monitored quantum system and the classical filtered measurement record has recently been shown to be described by a quantum Fokker-Planck master equation [Phys. Rev. Lett. 129, 050401 (2022)]. We present a deterministic approach to compute the steady state of the system and detector. The method is shown to become particularly efficient in the absence of feedback, which we exploit to develop a perturbative approach valid for weak feedback. We show that through this method we can extract the full counting statistics of the signal, the quantum-classical mutual information between system and signal, as well as the Fisher information of the signal, which can be used for sensing applications. Our results are illustrated with both single-qubit models, as well as the spin chains governed by the one-dimensional transverse field Ising model or the Lipkin-Meshkov-Glick model.
format Preprint
id arxiv_https___arxiv_org_abs_2507_06303
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Extracting filtered signal statistics of continuously measured quantum systems
Kiely, Anthony
Landi, Gabriel T.
Quantum Physics
The joint state of a continuously monitored quantum system and the classical filtered measurement record has recently been shown to be described by a quantum Fokker-Planck master equation [Phys. Rev. Lett. 129, 050401 (2022)]. We present a deterministic approach to compute the steady state of the system and detector. The method is shown to become particularly efficient in the absence of feedback, which we exploit to develop a perturbative approach valid for weak feedback. We show that through this method we can extract the full counting statistics of the signal, the quantum-classical mutual information between system and signal, as well as the Fisher information of the signal, which can be used for sensing applications. Our results are illustrated with both single-qubit models, as well as the spin chains governed by the one-dimensional transverse field Ising model or the Lipkin-Meshkov-Glick model.
title Extracting filtered signal statistics of continuously measured quantum systems
topic Quantum Physics
url https://arxiv.org/abs/2507.06303