Quantum Networking II and Quantum Memories

Leveraging the complementary strengths of different types of qubits in quantum memories, hybrid quantum networking promises an advantage over single-species quantum networks for practical implementation of distributed tasks such as quantum computing, simulation, and data security [1-4]. Critical to a proposed method [5] improving entanglement generation rates in trapped-ion quantum networks are the ion’s ability to generate entanglement on-demand with single-photons, neutral-atoms’ ability to manipulate single-photons, and a photon’s ability to herald entanglement across long distances [6-7]. Here, we report on storing a quantum frequency converted (QFC) barium ion-entangled flying qubit in a rubidium quantum memory using electromagnetic induced transparency (EIT). Additionally, we present transmission characterization [8] of a multi-site, inter-city network, useful for communicating our frequency-converted, polarization-entangled flying qubit from the ion in the O-band. This work enables synthesizing hybrid components over a quantum network.

[1] K. Hammerer, A. S. Sørensen, and E. S. Polzik, Rev. Mod. Phys. 82, 1041–1093 (2010).

[2] S. Wehner D. Elkouss, R. Hanson, Science 362, eaam9288 (2018).

[3] A. R. McMillan et al., Sci Rep. 3, 2032 (2013). 

[4] A. Kumar, A. Suleymanzade, M. Stone, et al., Nature 615, 614–619 (2023). 

[5] J. Hannegan et al., Phys. Rev. A 103, 052433 (2021)

[6] J. Hannegan J. D. Siverns, and Q. Quraishi, Phys. Rev. A 106, 042441 (2022).

[7] J. D. Siverns et al., Sci. Adv. 5, eaav4651 (2019).

[8] W. McKenzie et al., Appl. Phys. Lett. 125, 164004 (2024)

Funding acknowledgement

Supported by Army Research Labs.