Quantum Fisher information for states in exponential form

Zhang Jiang

doi:10.1103/physreva.89.032128

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arXiv · 1310.2687

Quantum Fisher information for states in exponential form

Zhang Jiang

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Abstract

We derive explicit expressions for the quantum Fisher information and the symmetric logarithmic derivative (SLD) of a quantum state in the exponential form; the SLD is expressed in terms of the generator. Applications include quantum-metrology problems with Gaussian states and general thermal states. Specifically, we give the SLD for a Gaussian state in two forms, in terms of its generator and its moments; the Fisher information is also calculated for both forms. Special cases are discussed, including pure, degenerate, and very noisy Gaussian states.

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Zhang Jiang. 2014-03-31. Quantum Fisher information for states in exponential form. https://doi.org/10.1103/physreva.89.032128

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