2014/03/06 by Daniel Braun, Pu Jian, Olivier Pinel +1 · 1 citation
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1103/physreva.90.013821
published as Phys. Rev. A 90, 013821 (2014) · 19 pages, 3 figures
arxiv created 2014/03/06 · openalex publication_date 2014/07/16 · arxiv updated 2014/07/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Photon-subtracted and photon-added Gaussian states are amongst the simplest non-Gaussian states that are experimentally available. It is generally believed that they are some of the best candidates to enhance sensitivity in parameter extraction. We derive here the quantum Cram'er-Rao bound for such states and find that for large photon numbers photon subtraction or addition only leads to a small correction of the quantum Fisher information (QFI). On the other hand, a divergence of the QFI appears for very small squeezing in the limit of vanishing photon number in the case of photon subtraction, implying an arbitrarily precise measurement with almost no light. However, at least for the standard and experimentally established preparation scheme, the decreasing success probability of the preparation in that limit exactly cancels the divergence, leading to finite sensitivity per square root of Hz, when the duration of the preparation is taken into account.