NIST, the US’s National Institute of Standards and Technology, has announced a new record for accuracy in quantum computing, albeit for just a single qubit.
The researchers report an error rate that for the first time is low enough to meet (and in fact exceed) the theoretical standards needed to build the machines.
Kenton Brown, a NIST postdoc who led the project explains that the current scientific consensus is that one error per 10,000 logic operations is a low enough error rate to use error correction protocols in a quantum computer.
"If error rates are above that, you will introduce more errors in your correction operations than you are able to correct,”"he adds. "We've been able to show that we have good enough control over our single-qubit operations that our probability of error is 1 per 50,000 logic operations."
We can hear you from here: "What about the other qubit?" Well, patience, Grasshopper, this is complicated stuff. Even if they had a second qubit as part of the set up, it wouldn’t be on a desktop near you anytime soon, unless you have a handy supply of liquid helium.
The team caught their qubit in an ion trap where, instead of using a laser, they manipulated it with microwaves from an antenna built into the ion trap. This reduced errors that would have been introduced by instabilities in the laser’s "pointing and power".
The other trick they used was the old standby of cooling everything to 4.2K and keeping the whole shebang inside a copper vacuum chamber. This reduced the risk of errors from magnetic field fluctuations in the lab.
More at NIST here.