Integrated coplanar waveguide coil on diamond for enhanced homogeneous broadband NV magnetometry

Area of Science:

• Quantum sensing
• Diamond physics
• Microwave engineering

Background:

• Nitrogen-vacancy (NV) centers in diamond are promising quantum sensors.
• High-sensitivity magnetometry requires homogeneous and intense microwave fields.
• Existing microwave delivery methods have limitations in homogeneity, bandwidth, and integration.

Purpose of the Study:

• To present a novel coplanar waveguide (CPW) gold coil integrated on a diamond substrate.
• To enable homogeneous addressing of large ensembles of NV centers for enhanced sensing.
• To overcome limitations of previous microwave delivery structures.

Main Methods:

• Fabrication of a coplanar waveguide (CPW) gold coil directly patterned on a 3 × 3 mm² diamond substrate.
• Optimization of critical geometrical parameters for the CPW coil.
• Characterization of the generated microwave field homogeneity and bandwidth.

Main Results:

• Achieved a homogeneous magnetic field with a coefficient of variation < 6% over a 0.5 mm² area.
• Demonstrated broad bandwidth suitable for various NV sensing applications.
• The integrated coil offers enhanced stability and heat dissipation.

Conclusions:

• The proposed CPW gold coil on diamond is a viable solution for generating homogeneous microwave fields for NV center quantum sensing.
• This integrated approach offers advantages in stability, scalability, and miniaturization for advanced magnetometry.
• The device performance confirms its suitability for high-precision sensing and fundamental studies.