Hybrid Quantum Repeater Chain with Trapped Rb Neutral Atom and Tm-doped AFC Quantum Memory*

To achieve the quantum internet, quantum repeaters are essential devices for long-distance quantum communication infrastructure. High-rate quantum repeaters, however, remain a formidable technological challenge requiring both efficient single photon sources and long-lived, multi-mode quantum memories. To meet these daunting requirements, hybrid approaches that combine the strengths of different physical hardware constitute a promising route. I will discuss our recent proposal for such a hybrid quantum repeater where single cavity-coupled Rubidium (Rb) atoms[1] can function as entangled single photon sources that are directly compatible both with telecom fibers and Thulium (Tm) doped crystal multi-mode quantum memories[2]. This combines the excellent single photon emission properties of single Rb atoms with the promising multi-mode capabilities of rare-Earth doped crystals enabling a robust and efficient quantum repeater. Importantly, I will discuss a novel scheme for generating optical-telecom photon entanglement from single cavity-coupled Rb atoms detailing both cavity, trapping, and pulse design for a robust generation despite common imperfections such as imperfect cavity coupling and laser polarization.

 

[1] Samutpraphoot, Polnop, et al. "Strong coupling of two individually controlled atoms via a nanophotonic cavity." Physical review letters 124.6 (2020): 063602.

[2] Davidson, Jacob H., et al. "Improved light-matter interaction for storage of quantum states of light in a thulium-doped crystal cavity." Physical Review A 101.4 (2020): 042333.