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内容記述 |
The realization of quantum networks is based on the entanglement of stationary qubits via flying photons. Therefore, a fundamental requirement is a single photon source that can efficiently generate indistinguishable photons for the entanglement generation. The group-IV vacancy centers in diamond have emerged as promising candidates due to their spectral stability benefiting from inversion symmetry and long spin coherence time. In particular, the lead-vacancy (PbV) center exhibits fourier-limited linewidths even above 10 K and is predicted to have millisecond-scale spin coherence time near 9 K, making it suitable for scalable quantum networks. Here, we report the indistinguishability of photons emitted from a single PbV center in diamond through a two-photon interference experiment, known as the Hong-Ou-Mandel (HOM) effect. Fluorescence from the PbV center was split into two paths and recombined at a HOM interferometer. Photon correlations were measured for parallel and orthogonal polarized schemes. In parallel polarization, a clear interference dip below 0.5 at zero time delay was observed, whereas for orthogonal polarization, the correlation function exceeded 0.5. These results confirm the generation of indistinguishable photons from a single PbV center, validating their potential as the solid-state quantum emitter. This work paves the way for the PbV-based application for quantum information processing. |