We demonstrate optical readout of ensembles of nitrogen-vacancy(NV) center spins in a bulk diamond sample via spin-to-charge conversion. A high power 594 nm laser is utilized to selectively ionize these paramagnetic defects in the spin state with a contrast of up to 12%. In comparison with the conventional 520 nm spin readout, spin-to-charge-conversion-based readout provides higher signal-to-noise ratio, with tenfold sensing measurement speedup for millisecond long pulse sequences. This level of performance was achieved for an NV- ionization of only 25%, limited by the ionization and readout laser powers. These observations pave the way to a range of high-sensitivity metrology applications where the use of NV- ensembles in bulk diamond has proven useful, including sensing and imaging of target materials overlaid on the diamond surface.
@article{arxiv.1809.07380,
title = {Spin readout via spin-to-charge conversion in bulk diamond nitrogen-vacancy ensembles},
author = {Harishankar Jayakumar and Siddharth Dhomkar and Jacob Henshaw and Carlos A. Meriles},
journal= {arXiv preprint arXiv:1809.07380},
year = {2018}
}