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arXiv · 1507.01941

Quantum fidelity for arbitrary Gaussian states

Leonardo Banchi·Samuel L. Braunstein·Stefano Pirandola
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Abstract

We derive a computable analytical formula for the quantum fidelity between two arbitrary multimode Gaussian states which is simply expressed in terms of their first- and second-order statistical moments. We also show how such a formula can be written in terms of symplectic invariants and used to derive closed forms for a variety of basic quantities and tools, such as the Bures metric, the quantum Fisher information and various fidelity-based bounds. Our result can be used to extend the study of continuous-variable protocols, such as quantum teleportation and cloning, beyond the current one-mode or two-mode analyses, and paves the way to solve general problems in quantum metrology and quantum hypothesis testing with arbitrary multimode Gaussian resources.

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Leonardo Banchi, Samuel L. Braunstein, Stefano Pirandola. 2015-07-07. Quantum fidelity for arbitrary Gaussian states. https://doi.org/10.1103/physrevlett.115.260501

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