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

TL;DR

This paper introduces a high-dynamic-range broadband magnetic-field sensor using ensemble nitrogen-vacancy centers in diamond, achieving fast measurement bandwidths and extended dynamic range suitable for practical applications.

Contribution

The work presents a novel magnetometry technique combining NV centers with a closed-loop frequency locking method, significantly extending dynamic range and bandwidth.

Findings

Achieved a measurement bandwidth of 10 kHz.

Extended dynamic range up to 4.3 mT, 86 times broader than intrinsic.

Demonstrated a sensitivity of 4.2 nT-Hz^{-1/2}.

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 the 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 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.