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arXiv · 1403.3830

Discriminating single-photon states unambiguously in high dimensions

Megan Agnew·Eliot Bolduc·Kevin J. Resch·Sonja Franke-Arnold·Jonathan Leach
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Abstract

The ability to uniquely identify a quantum state is integral to quantum science, but for non-orthogonal states, quantum mechanics precludes deterministic, error-free discrimination. However, using the non-deterministic protocol of unambiguous state discrimination (USD) enables error-free differentiation of states, at the cost of a lower frequency of success. We discriminate experimentally between non-orthogonal, high-dimensional states encoded in single photons; our results range from dimension $d=2$ to $d=14$. We quantify the performance of our method by comparing the total measured error rate to the theoretical rate predicted by minimum-error state discrimination. For the chosen states, we find a lower error rate by more than one standard deviation for dimensions up to $d=12$. This method will find immediate application in high-dimensional implementations of quantum information protocols, such as quantum cryptography.

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Megan Agnew, Eliot Bolduc, Kevin J. Resch, Sonja Franke-Arnold, Jonathan Leach. 2014-03-15. Discriminating single-photon states unambiguously in high dimensions. https://doi.org/10.1103/physrevlett.113.020501

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