Simultaneous Broadband Vector Magnetometry Using Solid-State Spins

TL;DR

This paper introduces a high-sensitivity, broadband, simultaneous vector magnetometer using NV centers in diamond, capable of measuring all magnetic field components quickly and accurately under various conditions.

Contribution

The work presents a novel solid-state vector magnetometer that measures all three magnetic field components simultaneously with high sensitivity and bandwidth, improving speed over sequential methods.

Findings

Achieves ~50 pT/√Hz sensitivity for each component.

Operates from near DC to 12.5 kHz bandwidth.

Provides 4x faster measurement compared to sequential NV orientation methods.

Abstract

We demonstrate a vector magnetometer that simultaneously measures all Cartesian components of a dynamic magnetic field using an ensemble of nitrogen-vacancy (NV) centers in a single-crystal diamond. Optical NV-diamond measurements provide high-sensitivity, broadband magnetometry under ambient or extreme physical conditions; and the fixed crystallographic axes inherent to this solid-state system enable vector sensing free from heading errors. In the present device, multi-channel lock-in detection extracts the magnetic-field-dependent spin resonance shifts of NVs oriented along all four tetrahedral diamond axes from the optical signal measured on a single detector. The sensor operates from near DC up to a $12.5$ kHz measurement bandwidth; and simultaneously achieves $\sim\!50$ pT/$\sqrt{\text{Hz}}$ magnetic field sensitivity for each Cartesian component, which is to date the highest demonstrated sensitivity of a full vector magnetometer employing solid-state spins. Compared to optimized devices interrogating the four NV orientations sequentially, the simultaneous vector magnetometer enables a $4\times$ measurement speedup. This technique can be extended to pulsed-type sensing protocols and parallel wide-field magnetic imaging.