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Quantum weak values

G. J. Pryde·J. L. O'Brien·A. G. White·T. C. Ralph·H. M. Wiseman
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Abstract

We experimentally determine weak values for a single photon's polarization, obtained via a weak measurement that employs a two-photon entangling operation, and postselection. The weak values cannot be explained by a semiclassical wave theory, due to the two-photon entanglement. We observe the variation in size of the weak value with measurement strength, obtaining an average measurement of the S_1 Stokes parameter more than an order of magnitude outside of the operator's spectrum for the smallest measurement strengths.

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G. J. Pryde, J. L. O'Brien, A. G. White, T. C. Ralph, H. M. Wiseman. 2005-08-19. Quantum weak values. https://doi.org/10.1103/physrevlett.94.220405

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