Enhanced Emission and Two-Photon Interference of Lead-Vacancy Centers in Diamond Solid Immersion Lenses

Koyo Hirai; Eiki Ota; Yiyang Chen; Ren Kato; Peng Wang; Toshiharu Makino; Takashi Taniguchi; Masashi Miyakawa; Shinobu Onoda; Mutsuko Hatano; Takayuki Iwasaki

arXiv · 2609.19220

Enhanced Emission and Two-Photon Interference of Lead-Vacancy Centers in Diamond Solid Immersion Lenses

Koyo Hirai·Eiki Ota·Yiyang Chen·Ren Kato·Peng Wang·Toshiharu Makino·Takashi Taniguchi·Masashi Miyakawa·Shinobu Onoda·Mutsuko Hatano·Takayuki Iwasaki

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Abstract

A negatively charged lead-vacancy (PbV-) center in diamond is a novel quantum system which can be operated at a high temperature above 4 K owing to its large ground state splitting. To unlock the quantum properties of the PbV- center, the enhancement of the fluorescence intensity is a key issue. Here, we demonstrate enhanced emission from PbV- centers by a factor of approximately 10 using solid immersion lenses (SILs) fabricated on rough diamond surface caused by high-temperature anneal over 2000°C. Resonant excitation reveals the narrow emission close to the transform-limited linewidth. Furthermore, we demonstrate two-photon interference using one single PbV- center in an SIL. This enhanced emission and indistinguishability will lead to further development of the PbV- center towards quantum network node applications.

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Koyo Hirai, Eiki Ota, Yiyang Chen, Ren Kato, Peng Wang, Toshiharu Makino, Takashi Taniguchi, Masashi Miyakawa, Shinobu Onoda, Mutsuko Hatano, Takayuki Iwasaki. 2026-09-16. Enhanced Emission and Two-Photon Interference of Lead-Vacancy Centers in Diamond Solid Immersion Lenses. https://arxiv.org/abs/2609.19220

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