The big advantage of these so-called nitrogen vacancies is that they’re easy to see (because they can be made to emit photons) which means they can be relatively easily addressed. They are also well isolated from many types of environmental interference and so can store qubits for relatively long periods of up to several hundred microseconds
New Technique for Mass Production of Nitrogen Vacancies
* cover the diamond with a thin layer of resist, through which they then blast an array of holes using electron beam lithography.
* In the next step, they then bombard the many-holed resist with accelerated nitrogen ions. So any nitrogen ions that pass through the holes created by the electron beams end up burying themselves in the diamond layer, creating a nitrogen vacancy under each hole.
* Toyli and co have carried out a proof-of-principle experiment to create a micrometer scale 60 x 60 array of nitrogen vacancies in a thin layer of diamond. They say that this creates nitrogen vacancies at a rate of 1000 per second, orders of magnitude faster than the current technique.
The team says this can be improved with better control over the number of nitrogen ions that end up being implanted under each hole in the resist. In this experiment, some 30 ions ended up in a volume of diamond normally expected to carry only on ion.