Effects of phase fluctuations on phase sensitivity and visibility of path-entangled photon Fock states
Bhaskar Roy Bardhan, Kebei Jiang, Jonathan P. Dowling · Physical Review A · 2013
We study effects of phase fluctuations on phase sensitivity and visibility of a class of robust path-entangled photon Fock states (known as $m{m}^{\ensuremath{'}}$ states) as compared to the maximally path-entangled NOON states in the presence of realistic phase fluctuations such as turbulence noise. Our results demonstrate that the $m{m}^{\ensuremath{'}}$ states, which are more robust than the NOON state against photon loss, perform equally well when subject to such fluctuations. We derive the quantum Fisher information with the phase-fluctuation noise and show that the phase sensitivity with parity detection for both of the above states saturates the quantum Cram\'er-Rao bound in the presence of such noise, suggesting that parity detection is an optimal detection strategy.