A tight Cramér-Rao bound for joint parameter estimation with a pure two-mode squeezed probe
arXiv:1702.02271 · doi:10.1016/j.physleta.2017.06.024
Abstract
We calculate the Holevo Cramér-Rao bound for estimation of the displacement experienced by one mode of an two-mode squeezed vacuum state with squeezing r and find that it is equal to 4exp(-2r). This equals the sum of the mean squared error obtained from a dual homodyne measurement, indicating that the bound is tight and that the dual homodyne measurement is optimal.
18 pages, 1 figure