  Ensembles of nitrogen-vacancy (NV) color centers in diamond hold promise of
ultraprecise magnetometery competing with SQUID detectors. By utilizing
advantages of dielectric materials such as very low losses for electromagnetic
field and therefore possibility to create high quality factor resonators with
strong concentration of the field in it we implemented a dielectric resonator
antenna for coherent manipulation of large ensemble of NV centers in diamond.
We reached average Rabi frequency of 10 MHz in the volume of 7 cubic
millimeters with standard deviation less than 1% at moderate pump power. This
result passes the way to improve sensitivity of cutting edge NV based
magnetometers by two orders of magnitude practically reaching SQUID level of
sensitivity.
