Illustration from Scientific Research

Comparison between the conventional scheme with coherent state (left) and the Fock state scheme (right) for displacement and phase sensing in a probe cavity with an ancillary qubit. The conventional metrology scheme has a sensitivity limit of 1/2 when measuring the displaced or rotated coherent states, while the Fock states provide an enhancement factor of sqrt(N) due to the fine structural features in their Wigner functions in the phase space.

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