Complete tomography of a high-fidelity solid-state entangled spin-photon qubit pair

Kristiaan De Greve, Peter L McMahon, Leo Yu, Jason S. Pelc, Cody Jones, Chandra M Natarajan, Na Young Kim, Eisuke Abe, Sebastian Maier, Christian Schneider, Martin Kamp, Sven Hoefling, Robert H Hadfield, Alfred Forchel, M. M. Fejer, Yoshihisa Yamamoto

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)

Abstract

Entanglement between stationary quantum memories and photonic qubits is crucial for future quantum communication networks. Although high-fidelity spin-photon entanglement was demonstrated in well-isolated atomic and ionic systems, in the solid-state, where massively parallel, scalable networks are most realistically conceivable, entanglement fidelities are typically limited due to intrinsic environmental interactions. Distilling high-fidelity entangled pairs from lower-fidelity precursors can act as a remedy, but the required overhead scales unfavourably with the initial entanglement fidelity. With spin-photon entanglement as a crucial building block for entangling quantum network nodes, obtaining high-fidelity entangled pairs becomes imperative for practical realization of such networks. Here we report the first results of complete state tomography of a solid-state spin-photon-polarization-entangled qubit pair, using a single electron-charged indium arsenide quantum dot. We demonstrate record-high fidelity in the solid-state of well over 90%, and the first (99.9%-confidence) achievement of a fidelity that will unambiguously allow for entanglement distribution in solid-state quantum repeater networks.

Original languageEnglish
Article number2228
Number of pages7
JournalNature Communications
Volume4
DOIs
Publication statusPublished - Jul 2013

Keywords

  • QUANTUM-DOT SPIN
  • SINGLE-PHOTON
  • LOCAL OPERATIONS
  • ATOM
  • DOWNCONVERSION
  • COMMUNICATION
  • PURIFICATION
  • REPEATERS
  • INTERFACE
  • CHANNELS

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