Entanglement between a Diamond Spin Qubit and a Photonic Time-Bin Qubit at Telecom Wavelength

Anna Tchebotareva; Sophie L N Hermans; Peter C Humphreys; Dirk Voigt; Peter J Harmsma; Lun K Cheng; Ad L Verlaan; Niels Dijkhuizen; Wim de Jong; Anaïs Dréau; Ronald Hanson

doi:10.1103/PhysRevLett.123.063601

Entanglement between a Diamond Spin Qubit and a Photonic Time-Bin Qubit at Telecom Wavelength

Phys Rev Lett. 2019 Aug 9;123(6):063601. doi: 10.1103/PhysRevLett.123.063601.

Authors

Anna Tchebotareva^{1

2}, Sophie L N Hermans^{1

3}, Peter C Humphreys^{1

3}, Dirk Voigt^{1

2}, Peter J Harmsma^{1

2}, Lun K Cheng^{1

2}, Ad L Verlaan^{1

2}, Niels Dijkhuizen^{1

2}, Wim de Jong^{1

2}, Anaïs Dréau^{1

3

4}, Ronald Hanson^{1

3}

Affiliations

¹ QuTech, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands.
² Netherlands Organisation for Applied Scientific Research (TNO), P.O. Box 155, 2600 AD Delft, Netherlands.
³ Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, Netherlands.
⁴ Laboratoire Charles Coulomb, Université de Montpellier and CNRS, 34095 Montpellier, France.

PMID: 31491180
DOI: 10.1103/PhysRevLett.123.063601

Abstract

We report on the realization and verification of quantum entanglement between a nitrogen-vacancy electron spin qubit and a telecom-band photonic qubit. First we generate entanglement between the spin qubit and a 637 nm photonic time-bin qubit, followed by photonic quantum frequency conversion that transfers the entanglement to a 1588 nm photon. We characterize the resulting state by correlation measurements in different bases and find a lower bound to the Bell state fidelity of ≥0.77±0.03. This result presents an important step towards extending quantum networks via optical fiber infrastructure.