Realization of high-dynamic-range broadband magnetic-field sensing with ensemble nitrogen-vacancy centers in diamond

Abstract

We present a new magnetometry method integrating an ensemble of nitrogen-vacancy (NV) centers in a single-crystal diamond with an extended dynamic range for monitoring a fast changing magnetic-field. The NV-center spin resonance frequency is tracked using a closed-loop frequency locked technique with fast frequency hopping to achieve a 10 kHz measurement bandwidth, thus allowing for the detection of fast changing magnetic signals up to 0.723 T/s. This technique exhibits an extended dynamic range subjected to the working bandwidth of the microwave source. This extended dynamic range can reach up to 4.3 mT, which is 86 times broader than the intrinsic dynamic range. The essential components for NV spin control and signal processing, such as signal generation, microwave frequency control, data processing, and readout, are integrated in a board-level system. With this platform, we demonstrate a broadband magnetometry with an optimized sensitivity of 4.2 nT Hz−1/2. This magnetometry method has the potential to be implemented in a multichannel frequency locked vector magnetometer suitable for a wide range of practical applications, such as magnetocardiography and high-precision current sensors.

High-Dynamic-Range Integrated NV Magnetometers

“…When the magnetic field intensity exceeded the intrinsic dynamic range of NV resonance, the system would be unable to detect magnetic field changes in real-time, thus limiting its detection range in practical applications. To overcome this challenge, Wang Cao et al employed a rapid-frequency-hopping technology to detect rapidly changing magnetic signals at 0.723 T/s [29]. Their designed NV center magnetometer extended the inherent dynamic range to 4.3 mT while maintaining a noise figure of 4.2 nT/Hz 1/2 .…”

A wide dynamic range diamond quantum sensor as an electric vehicle battery monitor

“…Diamond quantum sensors including NV-centre are characterized by high sensitivities [ 2 – 22 ] and wide dynamic ranges [ 23 – 25 ], and are suitable for automotive applications. Thus, we investigated a diamond quantum sensor for EV battery monitoring and have realized an accuracy of 10 mA and dynamic range of ±1000 A [ 1 ].…”