2015/07/07 by Leonardo Banchi, Samuel L. Braunstein, Stefano Pirandola · 4 citations
Physics and Astronomy · Mathematics · #quant-ph #cond-mat.other #math-ph #math.MP #physics.optics
paper · pdf · doi:10.1103/physrevlett.115.260501
published as Phys. Rev. Lett. 115, 260501 (2015) · Main text (4 pages) plus Appendices
arxiv created 2015/07/07 · arxiv updated 2015/12/23
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.