Hyperfine level structure in nitrogen-vacancy centers near the ground-state level anticrossing

Abstract

Energy levels of nitrogen-vacancy centers in diamond were investigated using optically detected magnetic-resonance spectroscopy near the electronic ground-state level anticrossing (GSLAC) at an axial magnetic field around 102.4 mT in a diamond sample with a nitrogen concentration of 1 ppm. By applying radiowaves in the frequency ranges from 0 to 40 MHz and from 5.6 to 5.9 GHz, we observed transitions that involve energy levels mixed by the hyperfine interaction. We developed a theoretical model that describes the level mixing, transition energies, and transition strengths between the ground-state sublevels, including the coupling to the nuclear spin of the NV center's 14 N and 13 C atoms. The calculations were combined with the experimental results by fitting the ODMR spectral lines based on a theoretical model, which yielded information about the polarization of nuclear spins. This study is important for the optimization of experimental conditions in GSLAC-based applications, e.g., microwave-free magnetometry and microwave-free nuclear-magnetic-resonance probes.

Photoluminescence at the ground state level anticrossing of the nitrogen-vacancy center in diamond

“…The latter can be characterized by 0 0 monopole, 1 0 dipole, and 2 0 quadrupole moments that correspond to population, orientation, and alignment, respectively. 22 Orientation and alignment can be obtained from quantities p m defining the probability of finding the nuclear spin in state |m as…”

“…Besides the optical signal, optically detected magnetic resonance (ODMR) signal of a NV ensemble has been recently recorded. 22 Recently, the ground state level anticrossing at zero magnetic field and related phenomena have attracted considerable attention. 23,24 As increasing number of applications rely on LAC signals of single or ensemble NV systems, quantitative description of the most relevant environmental couplings is essential for further development and engineering of these applications.…”

$\textit{Ab initio}$ and group theoretical study of properties of the $\text{C}_\text{2}\text{C}_\text{N}$ carbon trimer defect in h-BN

“…In this figure, we have assumed the quartet state is further detuned from the doublets than the spin-orbit coefficient. Usually the spin-orbit coefficient is on the order of GHz [27] spin [29,40]. We only have to look at the magnetic component since 13 C has a nuclear spin of I = 1/2, and the electric component is due to the quadrupole moment of nuclei with spin I ≥ 1 [41].…”

Electrical readout microwave-free sensing with diamond

“…A remarkably sharp feature around 102.4 mT, indicates the GSLAC which occurs when the Zeeman shift of the |m s = −1 component equals to the zero-field splitting [11,20]. At around 51.2 mT, the observed features correspond to cross-relaxation between the NV center and P1 centers [20][21][22][23][24], where these two defects can exchange energy due to resonant transition frequencies [21]. The feature that appears near 59 mT corresponds to cross-relaxation between on-axis (along z) and off-axis NVs.…”