Mottola Roberto, Buser Gianni, Treutlein Philipp
Departement Physik, Universität Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
Phys Rev Lett. 2023 Dec 29;131(26):260801. doi: 10.1103/PhysRevLett.131.260801.
Scalability presents a central platform challenge for the components of current quantum network implementations that can be addressed by microfabrication techniques. We demonstrate a high-bandwidth optical memory using a warm alkali atom ensemble in a microfabricated vapor cell compatible with wafer-scale fabrication. By applying an external tesla-order magnetic field, we explore a novel ground-state quantum memory scheme in the hyperfine Paschen-Back regime, where individual optical transitions can be addressed in a Doppler-broadened medium. Working on the ^{87}Rb D_{2} line, where deterministic quantum dot single-photon sources are available, we demonstrate bandwidth-matching with hundreds of megahertz broad light pulses keeping such sources in mind. For a storage time of 80 ns we measure an end-to-end efficiency of η_{e2e}^{80 ns}=3.12(17)%, corresponding to an internal efficiency of η_{int}^{0 ns}=24(3)%, while achieving a signal-to-noise ratio of SNR=7.9(8) with coherent pulses at the single-photon level.
可扩展性是当前量子网络实现组件面临的核心平台挑战，微纳制造技术可解决这一问题。我们展示了一种使用热碱金属原子系综的高带宽光存储器，该存储器位于与晶圆级制造兼容的微纳制造蒸汽池中。通过施加外部特斯拉量级的磁场，我们探索了一种在超精细帕邢 - 巴克区域的新型基态量子存储方案，在该区域中，单个光学跃迁可在多普勒加宽介质中实现。基于存在确定性量子点单光子源的(^{87}Rb) (D_2)线开展工作，我们展示了与数百兆赫兹宽光脉冲的带宽匹配，并考虑到此类光源。对于80纳秒的存储时间，我们测量的端到端效率为(\eta_{e2e}^{80 ns}=3.12(17)%)，对应于零纳秒时的内部效率为(\eta_{int}^{0 ns}=24(3)%)，同时在单光子水平的相干脉冲下实现了信噪比为(SNR = 7.9(8))。
