Recent developments in magnetic field sensing with negatively charged nitrogen-vacancy centers (NV) in diamond employ magnetic-field (MF) dependent features in the photoluminescence (PL) and eliminate the need for microwaves (MW). Here, we study two approaches towards improving the magnetometric sensitivity using the ground-state level anti-crossing (GSLAC) feature of the NV center at a background MF of 102.4\,mT. Following the first approach, we investigate the feature parameters for precise alignment in a dilute diamond sample; the second approach extends the sensing protocol into absorption via detection of the GSLAC in the diamond transmission of a 1042\,nm laser beam. This leads to an increase of GSLAC contrast and results in a magnetometer with a sensitivity of 0.45\,nT/Hz and a photon shot-noise limited sensitivity of 12.2 pT/Hz.
@article{arxiv.1701.06838,
title = {Level anti-crossing magnetometry with color centers in diamond},
author = {Huijie Zheng and Georgios Chatzidrosos and Arne Wickenbrock and Lykourgos Bougas and Reinis Lazda and Andris Berzins and Florian Helmuth Gahbauer and Marcis Auzinsh and Ruvin Ferber and Dmitry Budker},
journal= {arXiv preprint arXiv:1701.06838},
year = {2017}
}