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arXiv · 2207.00019

Experimental demonstration of optimal unambiguous two-out-of-four quantum state elimination

Jonathan W. Webb·Ittoop V. Puthoor·Joseph Ho·Jonathan Crickmore·Emma Blakely·Alessandro Fedrizzi·Erika Andersson
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Abstract

A core principle of quantum theory is that non-orthogonal quantum states cannot be perfectly distinguished with single-shot measurements. However, it is possible to exclude a subset of non-orthogonal states without error in certain circumstances. Here we implement a quantum state elimination measurement which unambiguously rules out two of four pure, non-orthogonal quantum states -- ideally without error and with unit success probability. This is a generalised quantum measurement with six outcomes, where each outcome corresponds to excluding a pair of states. Our experimental realisation uses single photons, with information encoded in a four-dimensional state using optical path and polarisation degrees of freedom. The prepared state is incorrectly ruled out up to $3.3(2)\%$ of the time.

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Jonathan W. Webb, Ittoop V. Puthoor, Joseph Ho, Jonathan Crickmore, Emma Blakely, Alessandro Fedrizzi, Erika Andersson. 2022-06-30. Experimental demonstration of optimal unambiguous two-out-of-four quantum state elimination. https://doi.org/10.1103/physrevresearch.5.023094

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