Continuous spectral hole burning and spin-level population oscillations are studied in an inhomogeneously broadened diamond-based spin ensemble composed of substitutional nitrogen and nitrogen-vacancy centres created through neutron irradiation and annealing. The burnt spectral features highlight a detuning-dependent homogeneous hole linewidth that is up to three orders of magnitude narrower than the total inhomogeneous ensemble linewidth. Continuous population oscillations are observed to quickly decay beyond a pump and probe detuning of 5 Hz, and are numerically modelled using a five-level system of coupled rate equations. Fourier analysis of these oscillations highlight discrete 13C hyperfine interactions, with energies within the inhomogeneous ensemble linewidth, as well as suspected nuclear 3/2-spin coupled signatures likely related to the 7Li byproduct of neutron irradiation.
@article{arxiv.1909.01050,
title = {Continuous microwave hole burning and population oscillations in a diamond spin ensemble},
author = {Haitham A. R. El-Ella and Alexander Huck and Ulrik L. Andersen},
journal= {arXiv preprint arXiv:1909.01050},
year = {2019}
}