Magnetic field imaging with NV ensembles

TL;DR

This paper presents a novel method for imaging spatial magnetic fields using NV center ensembles on diamond, achieving high resolution and sensitivity suitable for bioimaging applications.

Contribution

The authors demonstrate a new NV-based magnetic imaging technique with sub-micron resolution and discuss improvements for bioimaging applications.

Findings

Achieved sub-micron resolution magnetic field imaging

Sensitivity of approximately 100 nT/√Hz per pixel

Potential for real-time bioimaging of neuronal activity

Abstract

We demonstrate a method of imaging spatially varying magnetic fields using a thin layer of nitrogen-vacancy (NV) centers at the surface of a diamond chip. Fluorescence emitted by the two-dimensional NV ensemble is detected by a CCD array, from which a vector magnetic field pattern is reconstructed. As a demonstration, AC current is passed through wires placed on the diamond chip surface, and the resulting AC magnetic field patterns are imaged using an echo-based technique with sub-micron resolution over a 140 \mu m x 140 \mu m field of view, giving single-pixel sensitivity ~100 nT/\sqrt{Hz}. We discuss ongoing efforts to further improve sensitivity and potential bioimaging applications such as real-time imaging of activity in functional, cultured networks of neurons.