Although most work so far has focused on the NV– optical and spin properties, control of the charge state promises complementary opportunities. One intriguing possibility is the long-term storage of information. Our group is presently using multi-color optical microscopy to read, write, and reset arbitrary data sets in diamond with 2-D binary bit density comparable to present digital-video-disk (DVD) technology. Leveraging on the singular dynamics of NV– ionization, we encode information on different planes of the diamond crystal with no cross talk, hence extending the storage capacity to three dimensions.
Ongoing work in our group is aimed at correlating the center’s charge state and nuclear spin polarization of the nitrogen host as a route to sub-diffraction data storage. In combination with super-resolution microscopy techniques, control of individual NVs within a dense ensemble promises a storage capacity exceeding 1017 bytes/cm3, several orders of magnitude above present technology.