Ultra-sensitive Diamond Magnetometry Using Optimal Dynamic Decoupling

TL;DR

This paper introduces an advanced diamond magnetometry method using optimal dynamic decoupling to significantly enhance sensitivity, enabling detection of extremely weak magnetic fields at room temperature.

Contribution

It demonstrates a novel application of optimal dynamic decoupling to extend coherence times in NV diamond magnetometers, improving sensitivity without sacrificing spatial resolution.

Findings

Achieved magnetometer sensitivities as low as 5 pT/Hz^{1/2}.

Extended NV center coherence times to the spin bath's self-correlation time.

Provided a complementary approach to existing methods for enhancing magnetic sensitivity.

Abstract

New magnetometry techniques based on Nitrogen Vacancy (NV) defects in diamond have received much attention of late as a means to probe nanoscale magnetic environments. The sensitivity of a single NV magnetometer is primarily determined by the transverse spin relaxation time, $T_2$. Current approaches to improving the sensitivity employ crystals with a high NV density at the cost of spatial resolution, or extend $T_2$ via the manufacture of novel isotopically pure diamond crystals. We adopt a complementary approach, in which optimal dynamic decoupling techniques extend coherence times out to the self-correlation time of the spin bath. This suggests single spin, room temperature magnetometer sensitivities as low as 5\,pT\,Hz$^{-1/2}$ with current technology.