General Cramér-Rao Bound for Parameter Estimation using Gaussian Multimode Quantum Resources
Olivier Pinel, Nicolas Treps, Claude Fabre, Julien Fade · International Conference on Quantum Information · 2011
Multimode Gaussian quantum light, which includes coherent light, but also all kinds of multimode squeezed and/or multipartite quadrature entangled states, is a very general and powerful quantum resource that is now currently produced in various laboratories in the world, and is successfully used in various applications to quantum information processing[1]. In contrast to non-classical states based on the manipulation of Fock states (such as the NOON states), such quantum light can be produced with very high values of the mean photon number N (up to 1016). It is therefore a very good candidate for quantum metrology purposes, i.e. to improve as much as possible the estimation of a parameter p that is encoded on the spatio-temporal variation of a light beam, as all the limits in parameter estimation scale with some inverse power of N.