How to bury an ion (and find it again later)

Buried ions

The future of computing depends on our ability to bury single ions within the crystal structure of silicon and diamond in a way that allows us to find them again, quickly and repeatably.

The burying part of all this isn’t difficult: simply aim a beam of ions at a substrate and you can be pretty sure one or two of them will end up buried inside the crystal structure. The trick is to know where they’re buried so you can find them again later.

That’s a trick that Thomas Schenkel and pals at the Lawrence Berkeley National Laboratory overlooking San Francisco, seem to have perfected for the first time. Their technique is to fire the ion beam through a hole in the tip of a scanning force microscope. The hole defines the position of the burial while the scanning force microscope can easily find the location again later.

Schenkel has used the technique to bury nitrogen atoms in diamond and antimony in silicon, which is impressive. (The team even says it has discovered that antimony doesn’t migrate when the substrate is later heated, which is an important result in itself. Ions that move after you bury them are difficult to find later!)

But the bigger picture is that ion burial is one of the enabling technologies that will make quantum computing possible. So it’s just possible that Schenkel and co have created the first facility in which quantum computers will be forged.

Ref: Single-atom Doping for Quantum Device Development in Diamond and Silicon

One Response to “How to bury an ion (and find it again later)”

  1. J. Sapan says:

    I don’t contest that this is interesting, neat, and important work. However, There seems to be an assumption that quantum computing must be the future of computing and that this particular way of making a quantum bit is the only way it will ever happen. Both these assumptions are highly debatable. Also, the final sentence is the kind of hype I’d expect from a journalist, not someone who actually understands how science and technology work.