Integrated spin-wave quantum memory

Tian-Xiang Zhu; Ming-Xu Su; Chao Liu; Yu-Ping Liu; Chao-Fan Wang; Pei-Xi Liu; Yong-Jian Han; Zong-Quan Zhou; Chuan-Feng Li; Guang-Can Guo

doi:10.1093/nsr/nwae161

Integrated spin-wave quantum memory

Natl Sci Rev. 2024 May 1;11(11):nwae161. doi: 10.1093/nsr/nwae161. eCollection 2024 Nov.

Authors

Tian-Xiang Zhu^{1

2}, Ming-Xu Su^{1

2}, Chao Liu^{1

2}, Yu-Ping Liu^{1

2

3}, Chao-Fan Wang^{1

2}, Pei-Xi Liu^{1

2}, Yong-Jian Han^{1

2

3}, Zong-Quan Zhou^{1

2

3}, Chuan-Feng Li^{1

2

3}, Guang-Can Guo^{1

2

3}

Affiliations

¹ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China.
² CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
³ Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China.

Abstract

Photonic integrated quantum memories are essential for the construction of scalable quantum networks. Spin-wave quantum storage, which can support on-demand retrieval with a long lifetime, is indispensable for practical applications, but has never been demonstrated in an integrated solid-state device. Here, we demonstrate spin-wave quantum storage based on a laser-written waveguide fabricated in a ¹⁵¹Eu³⁺:Y₂SiO₅ crystal, using both the atomic frequency comb and noiseless photon-echo protocols. Qubits encoded with single-photon-level inputs are stored and retrieved with a fidelity of [Formula: see text], which is far beyond the maximal fidelity that can be obtained with any classical device. Our results underline the potential of laser-written integrated devices for practical applications in large-scale quantum networks, such as the construction of multiplexed quantum repeaters in an integrated configuration and high-density transportable quantum memories.

Keywords: integrated optics; quantum memory; quantum network; quantum optics.