| Autor: |
Rakonjac, Jelena V., Lago-Rivera, Dario, Seri, Alessandro, Mazzera, Margherita, Grandi, Samuele, de Riedmatten, Hugues |
| Rok vydání: |
2021 |
| Předmět: |
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| Zdroj: |
Physical Review Letters 127, 210502 (2021) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevLett.127.210502 |
| Popis: |
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 read-out and multimode operation are additional precious assets that will benefit the communication rate. In this work 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 non-degenerate parametric down-conversion, featuring energy-time entanglement between the telecom-wavelength idler and a visible signal photon. The latter is stored in a Pr$^{3+}$:Y$_2$SiO$_5$ 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 CHSH inequality, and $77(2)\%$ for spin-wave storage. Taking advantage of the on-demand read-out from the spin state, we extend the entanglement storage in the quantum memory for up to 47.7~$\mu$s, which could allow for the distribution of entanglement between quantum nodes separated by distances of up to 10 km. |
| Databáze: |
arXiv |
| Externí odkaz: |
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