Optically addressable atomic defects in solids are promising building blocks for future quantum communication technologies. The silicon-on-insulator (SOI) platform is an ideal host for such defects as it benefits from technologically mature silicon photonics and electronics. The novel T center in silicon offers telecommunication O-band optical transitions as well as a doublet ground state spin manifold with a long coherence time, making it a prime candidate for building quantum repeater devices. However, T centers’ weak coherent zero phonon line (ZPL) emission rate stands as an obstacle to their use in quantum networking applications. Here, by integrating single T centers with a low-loss, small mode-volume photonic crystal cavity on SOI, we demonstrate cavity-enhanced fluorescence emission from a single T center with an enhancement factor up to F = 6.89. Leveraging nanophotonic circuits and an angle-polished fiber for light coupling, the system achieves efficient ZPL photon extraction reaching an average outcoupling rate of 73.3 kHz. Lastly, by solving the Lindblad master equation, we extract the T-center-cavity coupling parameters and elucidate the cavity quantum electrodynamics of the coupled system. This work represents a major step towards utilizing single T centers in silicon for quantum information processing and networking applications.
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This content will become publicly available on September 9, 2025
Purcell Enhancement and Spin Spectroscopy of Silicon Vacancy Centers in Silicon Carbide Using an Ultrasmall Mode-Volume Plasmonic Cavity
Silicon vacancy (VSi) centers in 4H-silicon carbide have emerged as a strong candidate for quantum networking applications due to their robust electronic and optical properties, including a long spin coherence lifetime and bright, stable emission. Here, we report the integration of VSi centers with a plasmonic nanocavity to Purcell enhance the emission, which is critical for scalable quantum networking. Employing a simple fabrication process, we demonstrate plasmonic cavities that support a nanoscale mode volume and exhibit an increase in the spontaneous emission rate with a measured Purcell factor of up to 48. In addition to investigating the optical resonance modes, we demonstrate an improvement in the optical stability of the spin-preserving resonant optical transitions relative to the radiation-limited value. The results highlight the potential of nanophotonic structures for advancing quantum networking technologies and emphasize the importance of
optimizing emitter−cavity interactions for efficient quantum photonic applications.
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- Award ID(s):
- 2137828
- PAR ID:
- 10541578
- Publisher / Repository:
- Nano Letters
- Date Published:
- Journal Name:
- Nano Letters
- ISSN:
- 1530-6984
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Novel T centers in silicon hold great promise for quantum networking applications due to their telecom band optical transitions and the long-lived ground state electronic spins. An open challenge for advancing the T center platform is to enhance its weak and slow zero phonon line (ZPL) emission. In this work, by integrating single T centers with a low-loss, small mode-volume silicon photonic crystal cavity, we demonstrate an enhancement of the fluorescence decay rate by a factor of
F = 6.89. Efficient photon extraction enables the system to achieve an average ZPL photon outcoupling rate of 73.3 kHz under saturation, which is about two orders of magnitude larger than the previously reported value. The dynamics of the coupled system is well modeled by solving the Lindblad master equation. These results represent a significant step towards building efficient T center spin-photon interfaces for quantum information processing and networking applications. -
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