English
Related papers

Related papers: Robust estimation of the Quantum Fisher Informatio…

200 papers

Entanglement is widely regarded as an essential resource for a number of tasks and can in some cases be quantified by figures of merit related to those tasks. In quantum metrology, this is showcased by the connections between the quantum…

Quantum Physics · Physics 2026-03-24 Shaowei Du , Shuheng Liu , Matteo Fadel , Giuseppe Vitagliano , Qiongyi He

Entanglement is a defining feature of quantum mechanics that can be a resource in engineered and natural systems, but measuring entanglement in experiment remains elusive especially for large chemical systems. Most practical approaches…

Quantum Physics · Physics 2021-11-03 Andrew E. Sifain , Francesca Fassioli , Gregory D. Scholes

Multipartite entanglement, characterized by the quantum Fisher information (QFI), plays a central role in quantum-enhanced metrology and understanding quantum many-body physics. With a dynamical generalization of the Mazur-Suzuki relations,…

Quantum Physics · Physics 2023-04-04 Yu-Ran Zhang , Franco Nori

Current noise levels in physical realizations of qubits and quantum operations limit the applicability of conventional methods to characterize entanglement. In this adverse scenario, we follow a quantum variational approach to estimate the…

Quantum Physics · Physics 2022-09-16 A. D. Muñoz-Moller , L. Pereira , L. Zambrano , J. Cortés-Vega , A. Delgado

Quantum-enhanced sensing is commonly benchmarked using the quantum Fisher information (QFI), often interpreted as a direct indicator of achievable precision. However, this quantity acquires operational meaning only within a fully specified…

Quantum Physics · Physics 2026-03-10 Zdeněk Hradil , Jaroslav Řeháček

To optimize the entanglement detection, we formulate the metrologically operational entanglement condition in quantum Fisher information by maximizing the QFI on the measurement orbit. Specifically, we consider two classes of typical local…

Quantum Physics · Physics 2024-10-28 Ao-Xiang Liu , Ma-Cheng Yang , Cong-Feng Qiao

In this work, we propose new methods of parameter estimation using stochastic sampling quantum phase-space simulations. We show that it is possible to compute the quantum Fisher information (QFI) from semiclassical stochastic samples using…

Quantum Physics · Physics 2026-04-01 Thakur G. M. Hiranandani , Joseph J. Hope , Simon A. Haine

Quantum Fisher information matrix (QFIM) is a core concept in theoretical quantum metrology due to the significant importance of quantum Cram\'{e}r-Rao bound in quantum parameter estimation. However, studies in recent years have revealed…

Quantum Physics · Physics 2020-03-27 Jing Liu , Haidong Yuan , Xiao-Ming Lu , Xiaoguang Wang

We consider the general problem of estimating an unknown control parameter of an open quantum system. We establish a direct relation between the evolution of both system and environment and the precision with which the parameter can be…

Quantum Physics · Physics 2016-02-10 Katarzyna Macieszczak , Madalin Guta , Igor Lesanovsky , Juan P. Garrahan

Accurately characterizing multipartite entangled states is a critical challenge in quantum information processing. In this work, we focus on applying compressed sensing techniques to efficiently estimate the fidelity of…

Quantum Physics · Physics 2026-05-01 Farrokh Labib , David Nicholaeff , Vincent Russo , William J. Zeng

The quantum Fisher information (QFI) associated with a particular process applied to a many-body quantum system has been suggested as a diagnostic for the nature of the system's quantum state, e.g., a thermal density matrix vs. a pure state…

Statistical Mechanics · Physics 2023-04-05 Fernando Iniguez , Mark Srednicki

We study the time-dependent quantum Fisher information (QFI) in an open quantum system satisfying the Gorini-Kossakowski-Sudarshan-Lindblad master equation. We also study the dynamics of the system from an effective non-Hermitian dynamics…

Quantum Physics · Physics 2023-06-12 Zain H. Saleem , Anil Shaji , Stephen K. Gray

The Fisher information $F$ gives a limit to the ultimate precision achievable in a phase estimation protocol. It has been shown recently that the Fisher information for a linear two-mode interferometer cannot exceed the number of particles…

The quantum Fisher information (QFI) bounds the sensitivity of a quantum measurement, heralding the conditions for quantum advantages when compared with classical strategies. Here, we calculate analytical expressions for the QFI of…

Quantum Physics · Physics 2025-02-05 Jasper Kranias , Guillaume Thekkadath , Khabat Heshami , Aaron Z. Goldberg

Quantum metrology is a science about quantum measurements and it plays a key role in precision of quantum parameter estimation. Meanwhile, quantum coherence is an important quantum feature and quantum Fisher information (QFI) is an…

Quantum Physics · Physics 2025-10-30 Jun-Long Zhao , Li Yu , Ming Yang , Chui-Ping Yang

We introduce Quantum Functional Information (QFI), a new metric to quantify the rarity and utility of quantum states and circuits. Unlike standard measures such as fidelity or entropy, QFI captures the balance between functionality and…

Quantum Physics · Physics 2025-09-16 Rodrigo Pasti , Jonas Krause

Quantum entanglement is a quantum mechanical phenomenon where the quantum state of a many-body system with many degrees of freedom cannot be described independently of the state of each body with a given degree of freedom, no matter how far…

For a given quantum state used in sensing, the quantum Cram\'er-Rao bound (QCRB) sets a fundamental limit on the precision achievable by an unbiased estimator of an unknown parameter, determined by the inverse of the quantum Fisher…

Quantum Physics · Physics 2026-01-14 Andrew Kolmer Forbes , Marco A. Rodríguez-García , Ivan H. Deutsch

Multipartite entanglement is a crucial resource for advancing quantum technologies, with considerable research efforts directed toward achieving its rapid and scalable generation. In this work, we derive an analytical expression for the…

Quantum Physics · Physics 2025-10-21 Hai-Long Shi , Augusto Smerzi , Luca Pezzè

We study the role of quantum entanglement (particle entanglement and mode entanglement) in optical phase estimation by employing the first and second quantization formalisms of quantum mechanics. The quantum Fisher information (QFI) is…

Quantum Physics · Physics 2016-09-23 Jaspreet Sahota , Nicolás Quesada , Daniel F. V. James