Cavity-Enhanced Emission from a Silicon T Center.

Area of Science:

• Quantum computing
• Optics
• Materials Science

Background:

• Silicon T centers offer potential for optically active spin qubits in all-silicon devices.
• However, they suffer from long excited state lifetimes and low Debye-Waller factors, leading to dim emission and low zero-phonon line efficiency.
• Nanophotonic cavities can enhance radiative emission via the Purcell effect, improving efficiency.

Purpose of the Study:

• To demonstrate cavity-enhanced emission from a single T center in a nanophotonic cavity.
• To quantify the improvement in brightness and efficiency.
• To assess the potential for spin-photon interfaces.

Main Methods:

• Fabrication of a nanophotonic cavity integrated with a single T center.
• Measurement of optical emission properties before and after cavity integration.
• Analysis of zero-phonon line brightness, collection efficiency, and excited state lifetime.

Main Results:

• Achieved a 2-order of magnitude increase in zero-phonon line brightness compared to waveguide-coupled emitters.
• Demonstrated a 23% collection efficiency from the emitter to optical fiber.
• Observed an overall emission efficiency into the zero-phonon line of 63.4%.
• Measured a lifetime enhancement of 5, with a Purcell factor exceeding 18.

Conclusions:

• Cavity enhancement significantly boosts the performance of silicon T centers.
• These results demonstrate a viable path toward efficient spin-photon interfaces.
• The developed approach is crucial for advancing silicon photonics for quantum applications.