Pfender M., Aslam N., Simon P., Antonov D., Thiering G., Burk S., Fávaro De Oliveira F., Denisenko A., Fedder H., Meijer J., Garrido J.A., Gali A., Teraji T., Isoya J., Doherty M.W., Alkauskas A., Gallo A., Grüneis A., Neumann P., Wrachtrup J. Nano Letters; 17 (10): 5931 – 5937. 2017. 10.1021/acs.nanolett.7b01796. IF: 12.712
In recent years, solid-state spin systems have emerged as promising candidates for quantum information processing. Prominent examples are the nitrogen-vacancy (NV) center in diamond, phosphorus dopants in silicon (Si:P), rare-earth ions in solids, and VSi-centers in silicon-carbide. The Si:P system has demonstrated that its nuclear spins can yield exceedingly long spin coherence times by eliminating the electron spin of the dopant. For NV centers, however, a proper charge state for storage of nuclear spin qubit coherence has not been identified yet. Here, we identify and characterize the positively charged NV center as an electron-spin-less and optically inactive state by utilizing the nuclear spin qubit as a probe. We control the electronic charge and spin utilizing nanometer scale gate electrodes. We achieve a lengthening of the nuclear spin coherence times by a factor of 4. Surprisingly, the new charge state allows switching of the optical response of single nodes facilitating full individual addressability. © 2017 American Chemical Society.