Simultaneous Determination of Local Magnetic Fields and Sensor Orientation with Nitrogen-Vacancy Centers in Nanodiamond

TL;DR

This paper introduces a method to simultaneously determine the orientation of nanodiamond particles and the local magnetic fields they experience, enhancing their use in biomedical imaging and nanoscale sensing.

Contribution

A novel approach that uses multiple bias fields to unambiguously extract both particle orientation and local magnetic field from NV centers in nanodiamonds.

Findings

Validated method in bulk diamond with known orientation

Successfully applied to single nanodiamonds

Enables improved calibration for biomedical imaging

Abstract

Nitrogen-vacancy (NV) centers in nanodiamonds have emerged as a promising quantum sensing platform for biomedical imaging applications, yet random orientations of individual particles present significant challenges in large-scale sensor calibration. In this study, we demonstrate a novel approach to simultaneously determine each particle's crystallographic axes and the surrounding local vector magnetic field. Specifically, a minimum of four distinct bias fields is required to unambiguously extract both the orientation and the local field. We validate our method experimentally using NV centers in two scenarios: (1) in a bulk diamond with known crystal orientation as a proof of concept, and (2) on various single nanodiamonds to mimic real-world applications. Our work represents a crucial step towards unlocking the full potential of nanodiamonds for advanced applications such as in-situ biomedical imaging and nanoscale sensing in complex environments.