Subnanotesla Magnetometry with a Fiber-Coupled Diamond Sensor

R.L Patel,A.C Frangeskou,G.A Stimpson,E.C Nichols,D.J Twitchen,M.W Dale,L.Q Zhou,M.L Markham,A.M Edmonds,M.E Newton,B.G Breeze,B.L Green,G.W Morley,A Nikitin,W Thornley

doi:10.1103/physrevapplied.14.044058

Abstract

Nitrogen-vacancy centers (NVCs) in diamond are being explored for future quantum technologies, and in particular ensembles of NVC are the basis for sensitive magnetometers. We present a fiber-coupled NVC magnetometer with an unshielded sensitivity of $(310\ifmmode\pm\else\textpm\fi{}20)\phantom{\rule{0.2em}{0ex}}\mathrm{pT}/\sqrt{\mathrm{Hz}}$ in the frequency range of 10--150 Hz at room temperature. This takes advantage of low-strain ${}^{12}\mathrm{C}$ diamond, lenses for fiber coupling and optimization of microwave modulation frequency, modulation amplitude, and power. Fiber coupling means the sensor can be conveniently brought within 2 mm of the object under study.

Highlights

The sensing of magnetic fields using the nitrogenvacancy center (NVC) in diamond has seen rapid growth over the last decade due to the promise of high-sensitivity magnetometry with exceptional spatial resolution [1,2] along with a high dynamic range [3]
Nitrogen-vacancy centers (NVCs) in diamond are being explored for future quantum technologies, and in particular ensembles of NVC are the basis for sensitive magne√tometers
II, under this alignment only one of the four orientations of the NVC contribute to the magnetometry measurements; the other three NVC resonances are degenerate and occur at the same frequency

Summary

Introduction

The sensing of magnetic fields using the nitrogenvacancy center (NVC) in diamond has seen rapid growth over the last decade due to the promise of high-sensitivity magnetometry with exceptional spatial resolution [1,2] along with a high dynamic range [3]. The use of NVC ensembles rather than single centers improves the sensitivity while degrading the spatial resolution [3,4,5,6,7,8,9,10,11,12,13]. Recent advanc√ements have demonstrated ensemb√le sensitivities of 0.9 pT s for dc fields [14] and 0.9 pT/ Hz for ac fields [15]. These results have been limited to systems that are bulky and are typically fixed to optical tables.

Methods

Results

Conclusion