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Related papers: Multipartite-Entanglement Tomography of a Quantum …

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We show how to verify the metrological usefulness of quantum states based on the expectation values of an arbitrarily chosen set of observables. In particular, we estimate the quantum Fisher information as a figure of merit of metrological…

Quantum Physics · Physics 2017-04-25 Iagoba Apellaniz , Matthias Kleinmann , Otfried Gühne , Geza Toth

We consider the Ising model in a transverse field with long-range antiferromagnetic interactions that decay as a power law with their distance. We study both the phase diagram and the entanglement properties as a function of the exponent of…

Strongly Correlated Electrons · Physics 2013-02-08 Thomas Koffel , M. Lewenstein , Luca Tagliacozzo

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 investigate a quantum thermometry scheme based collision model with Gaussian systems. A key open question of these schemes concerns the scaling of the Quantum Fisher Information (QFI) with the number of ancillae. In qubit-based…

Quantum Physics · Physics 2024-10-28 Gabriel O. Alves , Marcelo A. F. Santos , Gabriel T. Landi

The role of two-point and multipartite entanglement at quantum phase transitions (QPTs) in correlated electron systems is investigated. We consider a bond-charge extended Hubbard model exactly solvable in one dimension which displays…

Strongly Correlated Electrons · Physics 2009-11-11 Alberto Anfossi , Paolo Giorda , Arianna Montorsi

We present a method to detect entanglement partitions of multipartite quantum systems, by exploiting their inherent symmetries. Structures like genuinely multipartite entanglement, $m$-separability and entanglement depth are detected as…

Quantum Physics · Physics 2025-11-19 Albert Rico , Dmitry Grinko , Robin Krebs , Lin Htoo Zaw

In the rapidly evolving field of quantum computing, optimizing quantum circuits for specific tasks is crucial for enhancing performance and efficiency. More recently, quantum sensing has become a distinct and rapidly growing branch of…

Quantum Physics · Physics 2025-09-01 Laxmisha Ashok Attisara , Sathish Kumar

We demonstrate that the quantum mutual information (QMI) is a useful probe to study many-body localization (MBL). First, we focus on the detection of a metal--insulator transition for two different models, the noninteracting…

Strongly Correlated Electrons · Physics 2017-01-11 Giuseppe De Tomasi , Soumya Bera , Jens H. Bardarson , Frank Pollmann

We derive several expressions for the quantum Fisher information matrix (QFIM) for the multi-parameter estimation of multi-mode Gaussian quantum states, the corresponding symmetric logarithmic derivatives, and conditions for saturability of…

Quantum Physics · Physics 2019-12-30 Dominik Šafránek

This study investigates the entanglement properties of quantum dots (QDs) under a universal Hamiltonian where the Coulomb interaction between particles (electrons or holes) decouples into a charging energy and an exchange coupling term.…

Quantum Physics · Physics 2024-08-13 Jahanfar Abouie , Daryoosh Vashaee

Recent experimental observation of weak ergodicity breaking in Rydberg atom quantum simulators has sparked interest in quantum many-body scars - eigenstates which evade thermalisation at finite energy densities due to novel mechanisms that…

We propose a scheme for parameter estimation with the steady states of non-Hermitian spin chains. The parameters to be estimated are encoded in the system via the external magnetic field that imposed on the first site of the chain. We…

Quantum Physics · Physics 2022-06-07 Huiqin Zhang , Jiasen Jin

The degree to which a pure quantum state is entangled can be characterized by the distance or angle to the nearest unentangled state. This geometric measure of entanglement is explored for bi-partite and multi-partite pure and mixed states.…

Quantum Physics · Physics 2009-05-18 Tzu-Chieh Wei

Despite of simplicity of the transverse antiferromagnetic Ising model with a uniform longitudinal field, its phases and involved quntum phase transitions (QPTs) are nontrivial in comparison to its ferromagnetic counterpart. For example,…

Statistical Mechanics · Physics 2025-11-19 Yun-Tong Yang , Hong-Gang Luo

Squashed entanglement and its universal upper bound, the quantum conditional mutual information, are faithful measures of bipartite quantum correlations defined in terms of multipartitions. As such, they are sensitive to the fine-grain…

Quantum Physics · Physics 2023-04-12 Alfonso Maiellaro , Francesco Romeo , Roberta Citro , Fabrizio Illuminati

We demonstrate that multipartite entanglement is able to characterize one-dimensional symmetry-protected topological order, which is witnessed by the scaling behavior of the quantum Fisher information of the ground state with respect to the…

Quantum Physics · Physics 2018-06-22 Yu-Ran Zhang , Yu Zeng , Heng Fan , J. Q. You , Franco Nori

In recent years, the performance of different entanglement indicators obtained directly from tomograms has been assessed in continuous-variable and hybrid quantum systems. In this paper, we carry out this task in the case of spin systems.…

Quantum Physics · Physics 2022-05-04 B. Sharmila , V. R. Krithika , Soham Pal , T. S. Mahesh , S. Lakshmibala , V. Balakrishnan

Multipartite entanglement is one of the crucial resources in quantum information processing tasks such as quantum metrology, quantum computing and quantum communications. It is essential to verify not only the multipartite entanglement, but…

Quantum Physics · Physics 2024-06-12 Kai Wu , Zhihua Chen , Zhen-Peng Xu , Zhihao Ma , Shao-Ming Fei

A quantum simulator is a restricted class of quantum computer that controls the interactions between quantum bits in a way that can be mapped to certain difficult quantum many-body problems. As more control is exerted over larger numbers of…

Quantum Physics · Physics 2018-02-07 J. Zhang , G. Pagano , P. W. Hess , A. Kyprianidis , P. Becker , H. Kaplan , A. V. Gorshkov , Z. -X. Gong , C. Monroe

We study quantum criticality in the infinite range Transverse-Field Ising Model. We find subtle differences with respect to the well-known single-site mean-field theory, especially in terms of gap, entanglement and quantum criticality. The…

Strongly Correlated Electrons · Physics 2024-08-28 Nicholas Curro , Kaeshav Danesh , Rajiv R. P. Singh