Multipulse Double-Quantum Magnetometry With Near-Surface Nitrogen Vacancy Centers

TL;DR

This paper introduces a multipulse double-quantum magnetometry technique using near-surface nitrogen-vacancy centers in diamond, achieving enhanced sensitivity to magnetic fields through dual frequency microwave pulsing and optimized pulse sequences.

Contribution

It presents a novel dual frequency microwave scheme for double-quantum magnetometry that works in arbitrary magnetic fields and improves sensitivity over traditional methods.

Findings

Enhanced magnetic field sensitivity with up to 2x SNR improvement in NMR detection.

Theoretical potential for 4x sensitivity enhancement.

Effective use of multipulse sequences up to 128 pulses.

Abstract

We discuss multipulse magnetometry that exploits all three magnetic sublevels of the S=1 nitrogen-vacancy center in diamond to achieve enhanced magnetic field sensitivity. Based on dual frequency microwave pulsing, the scheme works in arbitrary magnetic bias fields and is twice as sensitive to ac magnetic fields as conventional two-level magnetometry. We derive the spin evolution operator for dual frequency microwave excitation and show its effectiveness for double-quantum state swaps. Using multipulse sequences of up to 128 pulses under optimized conditions, we show enhancement of the SNR by up to a factor of 2 in detecting NMR statistical signals, with a 4 times enhancement theoretically possible.