Dopant-assisted stabilization of negatively charged single nitrogen-vacancy centers in phosphorus-doped diamond at low temperatures
Jianpei Geng, Tetyana Shalomayeva, Mariia Gryzlova, Amlan Mukherjee, S. Santonocito, Dzhavid Dzhavadzade, Durga Bhaktavatsala Rao Dasari, Hiromitsu Kato, Rainer Stöhr, Andrej Denisenko, Norikazu Mizuochi, Jörg Wrachtrup
Abstract
Abstract Charge state instabilities have been a bottleneck for the implementation of solid-state spin systems and pose a major challenge to the development of spin-based quantum technologies. Here we investigate the stabilization of negatively charged nitrogen-vacancy (NV − ) centers in phosphorus-doped diamond at liquid helium temperatures. Photoionization of phosphorous donors in conjunction with charge diffusion at the nanoscale enhances NV 0 to NV − conversion and stabilizes the NV − charge state without the need for an additional repump laser. The phosphorus-assisted stabilization is explored and confirmed both with experiments and our theoretical model. Stable photoluminescence-excitation spectra are obtained for NV − centers created during the growth. The fluorescence is continuously recorded under resonant excitation to real-time monitor the charge state and the ionization and recombination rates are extracted from time traces. We find a linear laser power dependence of the recombination rate as opposed to the conventional quadratic dependence, which is attributed to the photo-ionization of phosphorus atoms.