Old silicon microprocessors are reborn as spintronic quantum computers

Microprocessors are getting so tiny that they're actually small enough for quantum mechanics to start affecting their performance. That's bad news for traditional computing, but it's led to a breakthrough in spintronics, getting us a step closer to quantum computers.

Although "electronics" is often thought of as a sort of general technological short hand, it actually has a very specific meaning - all electronic devices take advantage of the controlled movement of electrons, using the individual subatomic particles as units of information. Spintronics, on the other hand, utilizes the spin of the electrons. (For an explanation of spin, check out this post.)

Since an electron can either be "spin-up" or "spin-down", this allows for a single electron to carry two pieces of information, as opposed to just one in traditional electronics. Spintronics is a big part of what will eventually become quantum computers, which makes use of various quantum phenomena to greatly increase the speed of its calculations. Finding suitable spintronic materials is an ongoing challenge in the slow march towards quantum computers.

It turns out the silicon transistors in microelectronics provide the perfect spintronic material as well. Deep inside the silicon is a small group of phosphorus atoms, which are known to be unusually good at maintaining their spin over relatively long periods. When a team of researchers at Australia's New South Wales University attached a sensor to the microelectronics, they were able to observe a spin lifetime of about six seconds. It may not sound like much, but a few seconds is actually a pretty long time for current spintronic materials, and the researchers are optimistic they can use these silicon microprocessors for the next generation of spintronic and quantum computing devices.

[Nature]