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.
@article{arxiv.1404.7480,
title = {Multipulse Double-Quantum Magnetometry With Near-Surface Nitrogen Vacancy Centers},
author = {H. J. Mamin and M. H. Sherwood and M. Kim and C. T. Rettner and K. Ohno and D. D. Awschalom and D. Rugar},
journal= {arXiv preprint arXiv:1404.7480},
year = {2015}
}
Comments
main text: 14 pages plus 4 pages figures (all in one pdf file); Supplementary material 13 pages, typos corrected in matrices on p. 6