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arXiv · 2412.17539

Two-Photon Interference of Photons from Remote Tin-Vacancy Centers in Diamond

Vladislav Bushmakin·Oliver von Berg·Colin Sauerzapf·Sreehari Jayaram·Andrej Denisenko·Cristina Tarín·Jens Anders·Vadim Vorobyov·Ilja Gerhardt·Di Liu·Jörg Wrachtrup
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Abstract

Scalable quantum networks rely on optical connections between long-lived qubits to distribute entanglement. Tin vacancies in diamond have emerged as promising long-lived qubits, offering extended spin coherence times at liquid helium temperatures and spin-dependent, highly coherent optical transitions for effective photon-based communication. Connecting remote nodes requires quantum interference of indistinguishable photons, which is challenging in an inhomogeneous solid-state environment. Here, we demonstrate a two-node experiment with tin vacancies in diamond, which exhibit a resonant frequency distribution spanning approximately 8 GHz. To overcome the frequency mismatch, we tune the resonant frequencies of one node using the Stark effect. We achieve tunability up to 4 GHz while maintaining optical coherence. As a demonstration, we achieve detuning-dependent remote two-photon interference between separate nodes, obtaining 80(6)% interference visibility without postprocessing when the defects' optical transitions are tuned into resonance, and 63(8)% with detuning up to 20 times their natural linewidths. These results highlight the potential of tin-vacancy centres in diamond for establishing robust optical links between remote quantum registers.

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Vladislav Bushmakin, Oliver von Berg, Colin Sauerzapf, Sreehari Jayaram, Andrej Denisenko, Cristina Tarín, Jens Anders, Vadim Vorobyov, Ilja Gerhardt, Di Liu, Jörg Wrachtrup. 2024-12-23. Two-Photon Interference of Photons from Remote Tin-Vacancy Centers in Diamond. https://arxiv.org/abs/2412.17539

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