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arXiv · 1510.04531

Certifying the presence of a photonic qubit by splitting it in two

Evan Meyer-Scott·Daniel McCloskey·Klaudia Gołos·Jeff Z. Salvail·Kent A. G. Fisher·Deny Hamel·Adán Cabello·Kevin J. Resch·Thomas Jennewein
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Abstract

We present an implementation of photonic qubit precertification that performs the delicate task of detecting the presence of a flying photon without destroying its qubit state, allowing loss-sensitive quantum cryptography and tests of nonlocality even over long distance. By splitting an incoming single photon in two via parametric down-conversion, we herald the photon's arrival from an independent photon source while preserving its quantum information with up to $92.3\pm0.6$ % fidelity. With reduced detector dark counts, precertification will be immediately useful in quantum communication.

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Evan Meyer-Scott, Daniel McCloskey, Klaudia Gołos, Jeff Z. Salvail, Kent A. G. Fisher, Deny Hamel, Adán Cabello, Kevin J. Resch, Thomas Jennewein. 2016-03-01. Certifying the presence of a photonic qubit by splitting it in two. https://doi.org/10.1103/physrevlett.116.070501

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