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 (a) 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 (b) 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. © 2012 American Physical Society.
Publication Source (Journal or Book title)
Physical Review A - Atomic, Molecular, and Optical Physics
Jiang, K., Brignac, C., Weng, Y., Kim, M., Lee, H., & Dowling, J. (2012). Strategies for choosing path-entangled number states for optimal robust quantum-optical metrology in the presence of loss. Physical Review A - Atomic, Molecular, and Optical Physics, 86 (1) https://doi.org/10.1103/PhysRevA.86.013826