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Time-reversal and super-resolving phase measurements

K. J. Resch·K. L. Pregnell·R. Prevedel·A. Gilchrist·G. J. Pryde·J. L. O'Brien·A. G. White
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Abstract

We demonstrate phase super-resolution in the absence of entangled states. The key insight is to use the inherent time-reversal symmetry of quantum mechanics: our theory shows that it is possible to \emph{measure}, as opposed to prepare, entangled states. Our approach is robust, requiring only photons that exhibit classical interference: we experimentally demonstrate high-visibility phase super-resolution with three, four, and six photons using a standard laser and photon counters. Our six-photon experiment demonstrates the best phase super-resolution yet reported with high visibility and resolution.

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K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O'Brien, A. G. White. 2006-08-08. Time-reversal and super-resolving phase measurements. https://doi.org/10.1103/physrevlett.98.223601

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