Precise phase measurements using an entangled coherent state

Knott, Paul and Dunningham, Jacob (2014) Precise phase measurements using an entangled coherent state. In: 2nd International Conference on Photonics, Optics and Laser Technology, 7 - 9 January 2014, Lisbon.

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Quantum entanglement offers the possibility of making measurements beyond the classical limit, however some issues still need to be overcome before it can be applied in realistic lossy systems. Recent work has used quantum Fisher information (QFI) to show that entangled coherent states (ECSs) may be useful for this purpose as they combine sub-classical phase precision capabilities with robustness (Joo et al., 2011). However, to date no effective scheme for measuring a phase in lossy systems using an ECS has been devised. Here we present a scheme that does just this. We show how one could measure a phase to a precision significantly better than that attainable by both unentangled ‘classical’ states and highly-entangled NOON states over a wide range of different losses. This brings quantum metrology closer to being a realistic and practical technology.

Item Type: Conference or Workshop Item (Paper)
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QC Physics > QC0170 Atomic physics. Constitution and properties of matter Including molecular physics, relativity, quantum theory, and solid state physics
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Depositing User: Jacob Dunningham
Date Deposited: 04 Jun 2015 14:53
Last Modified: 04 Jun 2015 14:53
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