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

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 (4, 1, 3) , Ronald Hanson (1, 3)

1 TU Delft - Delft University of Technology
2 TNO - The Netherlands Organisation for Applied Scientific Research
3 KI-NANO - Kavli Institute of Nanosciences [Delft]
4 L2C - Laboratoire Charles Coulomb

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.

Domaines: Physique Quantique [quant-ph]

Anna Tchebotareva, Sophie L. N. Hermans, Peter C. Humphreys, Dirk Voigt, Peter J. Harmsma, et al.. Entanglement between a Diamond Spin Qubit and a Photonic Time-Bin Qubit at Telecom Wavelength. Physical Review Letters, 2019, 123 (6), pp.063601. ⟨10.1103/PhysRevLett.123.063601⟩. ⟨hal-02379667⟩