The hope diamond. (credit: 350z33)
One of the more exciting things happening in physics at the moment is the development of quantum computers that may actually be able to do something useful. But, as we get closer to that glorious day, one of the big questions remaining is: what type of basic technology should be used as the basis for quantum computers? We know from our experience with classical computers that whatever technology wins is going to dominate for a long time. For instance, even though silicon-based integrated circuits were known to be worse than their germanium-based equivalent, silicon won for engineering reasons. Ever since, other semiconductor materials have remained niche, despite continued development. And they’ll likely stay niche until silicon is tapped out.
The decision on silicon is ancient history, and the consequences are set. But with quantum computers, we haven’t reached such a decision point yet. As such, a bazillion ideas are competing, and we get to sit on the sidelines and cheer the players on.
One approach, which has been quietly awaiting its next moment, is nitrogen-vacancy centers (NV- centers) in diamond. Although there have been a lot of exciting developments in terms of showing that NV- centers have excellent characteristics for qubits (a unit of quantum information), no one seems to be able to find a practical way to link anything more than a couple of qubits. Those days may be coming to an end, though, according to a recent study in Nature Photonics, the results of which could shift NV- centers off the bench, back onto the playing field.
Grids of defects make diamonds practical for quantum computing
