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Quantum 2.0 Conference and Exhibition

Quantum key distribution with atom-photon entanglement for an urban fiber link

Jonas Meiers, Christian Haen, Max Bergerhoff, Stephan Kucera, Jürgen Eschner

Published Jan 1, 2024• 0 citations
Publisher

Abstract

We implement a protocol for quantum key distribution based on atom-photon-entanglement over a 14-km urban dark-fiber link, using single photons from a 40Ca+-ion and active polarization correction.
DOI
10.1364/quantum.2024.qth3a.27

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Abstract We report on the implementation of quantum entanglement distribution and quantum state teleportation over a 14.4 km urban dark-fiber link, which is partially underground, partially overhead, and patched in several stations. We characterize the link for its use as a quantum channel and realize its active polarization stabilization. Using a type-II cavity-enhanced SPDC photon pair source, a 40 Ca + single-ion quantum memory, and quantum frequency conversion to the telecom C-band, we demonstrate photon-photon entanglement, ion-photon entanglement, and teleportation of a qubit state from the ion onto a remote telecom photon, all realized over the urban fiber link.
We report on the implementation of quantum entanglement distribution and quantum state teleportation over a 14.4-km urban dark-fiber link, which is partially underground, partially overhead, and patched in several stations. We characterize the link for its use as a quantum channel and realize its active polarization stabilization. Using a type-II cavity-enhanced SPDC photon pair source, a 40^{40}40Ca+^{+}+ single-ion quantum memory, and quantum frequency conversion to the telecom C-band, we demonstrate photon-photon entanglement, ion-photon entanglement, and teleportation of a qubit state from the ion onto a remote telecom photon, all realized over the urban fiber link.