2007/08/31 by Takafumi Ono, Holger F. Hofmann, Holger F Hofmann · 1 citation
Computer Science · Physics and Astronomy · #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum optics and atomic interactions #quant-ph
paper · pdf · doi:10.1088/0953-4075/41/9/095502
published as J. Phys. B: At. Mol. Opt. Phys. 41, 095502 (2008) · 21 pages, including 6 figures. Extended version gives more details on down-conversion efficiencies and clarifies the relation between phase sensitivity and squeezing. The title has been changed in order to avoid misunderstandings regarding these concepts
arxiv created 2008/04/01 · openalex publication_date 2008/04/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
It is shown that the addition of down-converted photon pairs to coherent laser light enhances the N -photon phase sensitivity due to the quantum interference between components of the same total photon number. Since most of the photons originate from the coherent laser light, this method of obtaining non-classical N -photon states is much more efficient than methods based entirely on parametrically down-converted photons. Specifically, it is possible to achieve an optimal phase sensitivity of about δϕ 2 = 1/ N 3/2 , equal to the geometric mean of the standard quantum limit and the Heisenberg limit, when the average number of down-converted photons contributing to the N -photon state approaches .