Results 31 to 40 of about 25,447 (255)

Multipartite entanglement of the topologically ordered state in a perturbed toric code

Physical Review Research, 2022
We demonstrate that multipartite entanglement, witnessed by the quantum Fisher information, can characterize topological quantum phase transitions in the spin-1/2 toric code model (TCM) on a square lattice with external fields.
Yu-Ran Zhang, Yu Zeng, Tao Liu, Heng Fan, J. Q. You, Franco Nori   +5 more
doaj   +1 more source

Fidelity and Fisher information on quantum channels

New Journal of Physics, 2017
The fidelity function for quantum states has been widely used in quantum information science and frequently arises in the quantification of optimal performances for the estimation and distinguishing of quantum states.
Haidong Yuan, Chi-Hang Fred Fung
doaj   +1 more source

Metrology and multipartite entanglement in measurement-induced phase transition [PDF]

Quantum
Measurement-induced phase transition arises from the competition between a deterministic quantum evolution and a repeated measurement process. We explore the measurement-induced phase transition through the Quantum Fisher Information in two different ...
Giovanni Di Fresco, Bernardo Spagnolo, Davide Valenti, Angelo Carollo   +3 more
doaj   +1 more source

Covariance and Fisher information in quantum mechanics [PDF]

Journal of Physics A: Mathematical and General, 2002
Variance and Fisher information are ingredients of the Cramer-Rao inequality. We regard Fisher information as a Riemannian metric on a quantum statistical manifold and choose monotonicity under coarse graining as the fundamental property of variance and Fisher information.
openaire   +2 more sources

Fisher information in quantum statistics [PDF]

Journal of Physics A: Mathematical and General, 2000
Braunstein and Caves (1994) proposed to use Helstrom's {\em quantum information} number to define, meaningfully, a metric on the set of all possible states of a given quantum system. They showed that the quantum information is nothing else than the maximal Fisher information in a measurement of the quantum system, maximized over all possible ...
Barndorff-Nielsen, O. E., Gill, R. D.
openaire   +7 more sources

Comment on ‘On the realisation of quantum Fisher information’ [PDF]

European Journal of Physics, 2017
Abstract It is shown that calculation of the momentum Fisher information of the quasi-one-dimensional hydrogen atom recently presented by Saha et al (2017 Eur. J. Phys. 38 025103
openaire   +2 more sources

Continuity of the quantum Fisher information [PDF]

Physical Review A, 2019
In estimating an unknown parameter of a quantum state the quantum Fisher information (QFI) is a pivotal quantity, which depends on the state and its derivate with respect to the unknown parameter. We prove the continuity property for the QFI in the sense that two close states with close first derivatives have close QFIs.
Rezakhani, A. T., Hassani, M., Alipour, S.   +3 more
openaire   +3 more sources

Fisher information as a probe of spacetime structure: relativistic quantum metrology in (A)dS

Journal of High Energy Physics, 2021
Relativistic quantum metrology studies the maximal achievable precision for estimating a physical quantity when both quantum and relativistic effects are taken into account.
Haoxing Du, Robert B. Mann
doaj   +1 more source

Quantum nonunital dynamics of spin-bath-assisted Fisher information

AIP Advances, 2016
The nonunital non-Markovian dynamics of qubits immersed in a spin bath is studied without any Markovian approximation. The environmental effects on the precisions of quantum parameter estimation are taken into account.
Xiang Hao, Yinzhong Wu
doaj   +1 more source

Quantum fisher information transfer and distribution in a hierarchical environment

Results in Physics
How quantum information encoded into a quantum state is lost, or transferred when an interest quantum system is coupled to its environment, is a fundamental issue in quantum information processing.
Youneng Guo, Qinglong Tian
doaj   +1 more source