Quantum phase estimation with lossy interferometers

Journal Article · Wed Jul 15 00:00:00 EDT 2009 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.80.013825· OSTI ID:21313343

Demkowicz-Dobrzanski, R; Banaszek, K ^[1]; Dorner, U; Lundeen, J S; Walmsley, I A ^[2]; Smith, B J ^[2]; Wasilewski, W ^[3]

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1. Institute of Physics, Nicolaus Copernicus University, Grudziadzka 5, PL-87-100 Torun (Poland)
2. Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)
3. Institute of Experimental Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland)

We give a detailed discussion of optimal quantum states for optical two-mode interferometry in the presence of photon losses. We derive analytical formulae for the precision of phase estimation obtainable using quantum states of light with a definite photon number and prove that maximization of the precision is a convex optimization problem. The corresponding optimal precision, i.e., the lowest possible uncertainty, is shown to beat the standard quantum limit thus outperforming classical interferometry. Furthermore, we discuss more general inputs: states with indefinite photon number and states with photons distributed between distinguishable time bins. We prove that neither of these is helpful in improving phase estimation precision.

• OSTI ID: 21313343
• Journal Information: Physical Review. A, Vol. 80, Issue 1; Other Information: DOI: 10.1103/PhysRevA.80.013825; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCURACY
INTERFEROMETERS
INTERFEROMETRY
OPTICS
OPTIMIZATION
PHOTONS
QUANTUM MECHANICS
VISIBLE RADIATION