Abstract:

Spin-photon interfaces augmented with quantum memories, such as those of defects in diamond, are prime candidates for quantum repeater nodes, the building blocks of the future quantum internet. Some of the challenges in achieving quantum repeaters with such systems include the ability to create robust and efficient entanglement of remote nodes through entanglement swapping; this is due to the probabilistic nature of Bell state measurements and the need for communication between nodes. An additional challenge involves the high-fidelity implementation of electron-nuclear entangling gates within a node. We propose to overcome these challenges through the triggered generation of graph states from quantum emitters and the design of fast, high-fidelity gates between the electron spin and the nuclear memory spin qubits. The performance-resource tradeoff of repeater graph states generated from emitters is also discussed, and estimates are provided for the regime where repeater graph states outperform other schemes.

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QuCoLiMaTalks are the weekly seminar of the collaborative research center TRR 306 QuCoLiMa (Quantum Cooperativity of Light and Matter). The talks are given by (external) experts, whose research falls within the scope of QuCoLiMa.