Broadband Light Extraction from Near-Surface NV Centers Using Crystalline-Silicon Antennas

Area of Science:

• Quantum optics
• Materials science
• Nanophotonics

Background:

• Nitrogen-vacancy (NV) centers in diamond are crucial quantum emitters.
• Efficiently extracting single photons from NV centers is challenging due to optical losses at the diamond-air interface.

Purpose of the Study:

• To develop a method for efficient broadband single-photon extraction from shallow NV centers in diamond.
• To overcome total internal reflection and Fresnel reflection using nanophotonic structures.

Main Methods:

• Fabrication of crystalline silicon (Si) antennas with high-index resonators on the diamond surface.
• Utilizing Si resonators to enhance photon extraction and provide Purcell enhancement.
• Simulations and experimental measurements of single-photon collection efficiency.

Main Results:

• Simulations predicted an enhancement of approximately 17 times in single-photon collection.
• Experiments demonstrated an enhancement of approximately 9 times, limited by alignment precision.
• The silicon antenna design avoids etching or damaging the diamond surface.

Conclusions:

• Crystalline silicon antennas offer an efficient and non-damaging approach for single-photon extraction from NV centers.
• This technique is applicable to other color centers in diamond and quantum emitters in wide-bandgap materials.
• The developed method significantly improves light collection for quantum information processing and sensing.