2010/12/31 by Marco G. Genoni, Stefano Olivares, Matteo G. A. Paris · 2 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.106.153603
published as Phys. Rev. Lett 106, 153603 (2011) · revised version, 4 pages, 4 figure
arxiv created 2011/01/17 · arxiv updated 2015/03/17
The measurement problem for the optical phase has been traditionally attacked for noiseless schemes or in the presence of amplitude or detection noise. Here we address estimation of phase in the presence of phase diffusion and evaluate the ultimate quantum limits to precision for phase-shifted Gaussian states. We look for the optimal detection scheme and derive approximate scaling laws for the quantum Fisher information and the optimal squeezing fraction in terms of the overall total energy and the amount of noise. We also found that homodyne detection is a nearly optimal detection scheme in the limit of very small and large noise.