Efficient Signal Processing for Low-Cost Magnetometry Using Nitrogen Vacancy Center in Diamond

Abstract

Nitrogen vacancy (NV) center-based magnetometers have progressed from proof-of-concept demonstrations to tabletop and compact devices as a consequence of the global focus on developing commercially viable solutions. Although the magnetometer’s sensor head has been shrunk, the platform’s electronics/test equipment form factor and requirements continue to be a significant barrier to the creation of low-cost solutions. As a result, the usability and accessibility of an NV-based magnetometer are constrained. In order to reduce sensor size, overall power consumption, and accessibility, we have developed a method based on the fast Fourier transform (FFT) to detect optically detected magnetic resonance in an ensemble of NV centers without the usage of cumbersome and expensive bench-top equipment, such as a lock-in amplifier. We perform a detailed comparative study of this protocol with the existing methods used for magnetic field sensing. We use this methodology to report a sensitivity of 126 nT/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sqrt {\text {Hz}}$ </tex-math></inline-formula> with the goal of developing protocols for low-cost magnetometry, making the magnetometer accessible with minimal components and laboratory setup, and serving as an easy way to teach enthusiasts even at the undergraduate level.