TY - JOUR
T1 - Entanglement between a telecom photon and an on-demand multimode solid-state quantum memory
AU - Rakonjac, Jelena V.
AU - Lago-Rivera, Dario
AU - Seri, Alessandro
AU - Mazzera, Margherita
AU - Grandi, Samuele
AU - de Riedmatten, Hugues
N1 - Funding Information:
The authors thank Andreas Lenhard for his contributions to the early design of the fibre interferometer. This project received funding from the European Union Horizon 2020 research and innovation program within the Flagship on Quantum Technologies through Grant No. 820445 (QIA) and under the Marie Skłodowska-Curie Grant agreements No. 713729 (ICFOStepstone 2) and no. 758461 (proBIST), from the European Union Regional Development Fund within the framework of the ERDF Operational Program of Catalonia 2014-2020 (Quantum CAT), from the Gordon and Betty Moore foundation through Grant No. GBMF7446 to H. d.-R., from the Government of Spain (PID2019-106850RB-I00; Severo Ochoa CEX2019-000910-S; BES-2017-082464), from Fundació Cellex, Fundació Mir-Puig, and from Generalitat de Catalunya (CERCA, AGAUR).
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/11/19
Y1 - 2021/11/19
N2 - Entanglement between photons at telecommunication wavelengths and long-lived quantum memories is one of the fundamental requirements of long-distance quantum communication. Quantum memories featuring on-demand readout and multimode operation are additional precious assets that will benefit the communication rate. In this Letter, we report the first demonstration of entanglement between a telecom photon and a collective spin excitation in a multimode solid-state quantum memory. Photon pairs are generated through widely nondegenerate parametric down-conversion, featuring energy-time entanglement between the telecom-wavelength idler and a visible signal photon. The latter is stored in a Pr3+:Y2SiO5 crystal as a spin wave using the full atomic frequency comb scheme. We then recall the stored signal photon and analyze the entanglement using the Franson scheme. We measure conditional fidelities of 92(2)% for excited-state storage, enough to violate a Clauser-Horne-Shimony-Holt inequality, and 77(2)% for spin-wave storage. Taking advantage of the on-demand readout from the spin state, we extend the entanglement storage in the quantum memory for up to 47.7 μs, which could allow for the distribution of entanglement between quantum nodes separated by distances of up to 10 km.
AB - Entanglement between photons at telecommunication wavelengths and long-lived quantum memories is one of the fundamental requirements of long-distance quantum communication. Quantum memories featuring on-demand readout and multimode operation are additional precious assets that will benefit the communication rate. In this Letter, we report the first demonstration of entanglement between a telecom photon and a collective spin excitation in a multimode solid-state quantum memory. Photon pairs are generated through widely nondegenerate parametric down-conversion, featuring energy-time entanglement between the telecom-wavelength idler and a visible signal photon. The latter is stored in a Pr3+:Y2SiO5 crystal as a spin wave using the full atomic frequency comb scheme. We then recall the stored signal photon and analyze the entanglement using the Franson scheme. We measure conditional fidelities of 92(2)% for excited-state storage, enough to violate a Clauser-Horne-Shimony-Holt inequality, and 77(2)% for spin-wave storage. Taking advantage of the on-demand readout from the spin state, we extend the entanglement storage in the quantum memory for up to 47.7 μs, which could allow for the distribution of entanglement between quantum nodes separated by distances of up to 10 km.
UR - http://www.scopus.com/inward/record.url?scp=85119960881&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.127.210502
DO - 10.1103/PhysRevLett.127.210502
M3 - Article
C2 - 34860116
SN - 0031-9007
VL - 127
JO - Physical Review Letters
JF - Physical Review Letters
IS - 21
M1 - 210502
ER -