Nitrogen-vacancy (NV) centers are probed all around the world on a daily basis. Here, in collaboration with a group of researches in the University of Latvia, we probe them as well, but first we turn on a magnetic field around them. Not any magnetic field, but such a field at which the hyperfine energy levels of the centers cross each other. Then we see how the NVs behave, mainly we look at transition rates and frequencies. Moreover, simulation were constructed, which allowed to compare the experimental results with a theoretical model.
The details of what happens to the NV centers as hyperfine levels cross are not fully understood. We make a step towards understanding how NVs work at this regime.
Figure, from
https://arxiv.org/abs/1805.01251 : Fluorescence intensity from the NV centers as a function of frequency. In black – experimental signal. In blue- theoretical model excluding the effect of 13C. In black – theoretical model including the effect of 13C. Each plot belongs to a different external magnetic field, whose value appears on the plot. The gray line follows the position of the (0,1) -> (1,0) heperfine transition.