Abstract
To acquire the best path-entangled photon Fock states for robust quantum-optical metrology with parity detection, we calculate phase information from a lossy interferometer by using twin entangled Fock states. We show that when loss is less than 50 twin entangled Fock states with large photon number difference give higher visibility, while when loss is higher than 50, the ones with less photon number difference give higher visibility; and twin entangled Fock states with large photon number difference give sub–shot-noise limit sensitivity for phase detection in a lossy environment. This result provides a reference on what particular path-entangled Fock states are useful for real world metrology applications.
- Received 28 April 2012
DOI:https://doi.org/10.1103/PhysRevA.86.013826
©2012 American Physical Society