Observing the charge state of substitutional nitrogen via nitrogen vacancy magnetometry

Defects in diamond have been widely explored as a potential system for quantum information processing. The negatively charged Nitrogen Vacancy (NV^-) center is of particular interest because its spin can be operated at ambient conditions and addressed optically with the help of low frequency microwave. It has been suggested that the spin state of the donor electron of the substitutional nitrogen defect (N_s) can be utilized as a quantum register for a spintronics bus [1]. Here, we use the NV center as a local probe to examine the ionization of small N_s ensembles in type 1b diamond. To this end, we implement double electron-electron resonance (DEER), [2] which we articulate with multi-color laser excitation to prepare and subsequently probe the local charge state in the N_s ensemble. We will also discuss the use of polarization transfer techniques from the NVs as a route to probe the spin resilience of photo-generated carriers throughout cycles of ionization from and re-trapping by N_s.
1. M. W. Doherty et al. Physical Review X, 6(4), 041035 (2016)
2. A. Laraoui et al. Nano Letters, 12(7), 3477 (2012)