Optimized Planar Microwave Antenna for Nitrogen Vacancy Center Based Sensing Applications.

Area of Science:

• Quantum Sensing
• Diamond Quantum Technologies
• Microwave Engineering

Background:

• Nitrogen vacancy (NV) centers in diamond are key components for spin-based quantum sensing.
• Coherent control of NV spin states using microwaves (2.5–3.5 GHz) is essential for their sensing capabilities.
• Existing methods for microwave control can be complex or lack uniformity over desired areas.

Purpose of the Study:

• To design and fabricate a novel stripline-based, planar, Ω-shaped microwave antenna.
• To enable reliable and efficient coherent manipulation of NV spins in diamond.
• To achieve uniform microwave fields over a significant area for scalable quantum sensing.

Main Methods:

• Utilized finite integral simulations to optimize the Ω-shaped antenna design.
• Fabricated the optimized antennas on a low-cost, transparent glass substrate.
• Characterized the microwave field uniformity and Rabi frequencies achieved by the antenna.

Main Results:

• Achieved highly uniform microwave fields across areas of approximately 400 × 400 μm².
• Demonstrated high Rabi frequencies of up to 10 MHz in an ensemble of NV centers.
• Successfully fabricated functional antennas on a cost-effective glass substrate.

Conclusions:

• The developed Ω-shaped antenna is effective for reliable manipulation of NV spins.
• This antenna design offers a promising solution for scalable and efficient diamond quantum sensing.
• The use of glass substrate presents a low-cost fabrication route for quantum device components.