Researchers Demonstrate Electrically Tunable Single-Photon Sources on Silicon for Quantum Networks
Scientists have fabricated electrically tunable single-photon emitters based on InGaAs quantum dots embedded in circular Bragg grating resonators grown directly on silicon, operating in the telecom O-band. The devices achieve a record quantum-confined Stark shift of ~16 nm (11 meV) at 4 K for quantum dots in nanophotonic structures at telecom wavelengths, along with high single-photon purity and a photon extraction efficiency of about 21.7%. The work provides a scalable, silicon-compatible platform that could accelerate the development of practical photonic quantum communication networks.
A research team has reported electrically contacted circular Bragg grating (eCBG) resonators incorporating InGaAs quantum dots grown monolithically on silicon, producing bright single-photon emission in the telecom O-band (~1300 nm). Using deterministic electron-beam lithography and a ridge-based vertical p-i-n diode architecture, the devices allow precise electrical control of individual emitters. The quantum-confined Stark shift of approximately 16 nm (11 meV) at 4 K is described as a record for quantum dots in nanophotonic structures at telecom wavelengths, enabling spatially separated emitters to be electrically tuned into spectral resonance with each other. Single-photon purity is exceptionally high, with a second-order autocorrelation value g²(0) = 0.0078 ± 0.0012 below saturation and g²(0) = 0.0183 ± 0.0021 at saturation under pulsed excitation. Notably, robust antibunching persists up to 77 K — the boiling point of liquid nitrogen — with g²(0) = 0.0663 ± 0.0056, making operation with liquid-nitrogen or compact Stirling cryocoolers feasible and reducing infrastructure demands. The combination of wide spectral tunability, high photon purity, efficient extraction, elevated-temperature operation, and direct silicon integration addresses several longstanding challenges simultaneously, positioning this platform as a promising building block for scalable photonic quantum networks.
What's missing
The study does not report photon indistinguishability (Hong-Ou-Mandel visibility), which is a critical metric for quantum networking applications alongside single-photon purity. Long-term device stability, yield across fabricated devices, and performance under realistic network operating conditions are not characterized.
What different sources said
- arXiv physicsCenter
Stark-tunable O-band single-photon sources based on deterministically fabricated quantum dot--circular Bragg gratings on silicon
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