Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

Intelligent Machines

Google Researchers Make Quantum Computing Components More Reliable

Researchers from a university and Google demonstrate a crucial error-correction step needed to make quantum computing practical.

Quantum computers will make it possible to perform all sorts of calculations at incredible speeds.

A solution to one of the key problems holding back the development of quantum computers has been demonstrated by researchers at Google and the University of California, Santa Barbara. Many more problems remain to be solved, but experts in the field say it is an important step toward a fully functional quantum computer. Such a machine could perform calculations that would take a conventional computer millions of years to complete.

Researchers from Google and the University of California, Santa Barbara, used this chip to demonstrate a crucial method needed to make quantum computers reliable.

The Google and UCSB researchers showed they could program groups of qubits—devices that represent information using fragile quantum physics—to detect certain kinds of error, and to prevent those errors from ruining a calculation. The new advance comes from researchers led by John Martinis, a professor at the University of California, Santa Barbara, who last year joined Google to set up a quantum computing research lab (see “Google Launches Effort to Build Its Own Quantum Computer”). Martinis now holds a joint position between UCSB and Google, leading work on superconducting aluminum chips that operate at a fraction of a degree above absolute zero. Most of the work behind the new results, reported today in the journal Nature, took place before Martinis joined Google.

Google has been exploring quantum computing since 2009, when it began collaborating with D-Wave Systems, a startup that sells what it calls “the first commercial quantum computer” (see “The CIA and Jeff Bezos Bet on Quantum Computing”). Microsoft also has a sizable quantum computing research program (see “Microsoft’s Quantum Mechanics”).

To make a quantum computer requires wiring together many qubits to work on information together. But the devices are error-prone because they represent bits of data—0s and 1s—using delicate quantum mechanical effects that are only detectable at super-cold temperatures and tiny scales. This allows qubits to achieve “superposition states” that are effectively both 1 and 0 at the same time, allowing quantum computers to take shortcuts through complex calculations. It also makes them vulnerable to heat and other disturbances that distort or destroy the quantum states used to encode information and perform calculations.

Much quantum computing research focuses on trying to get systems of qubits to detect and fix errors. Martinis’s group has demonstrated a piece of one of the most promising schemes for doing this, an approach known as surface codes. The researchers programmed a chip with nine qubits so that they monitored one another for errors called “bit flips,” where environmental noise causes a 1 to flip to a 0 or vice versa. The qubits could not correct bit flips, but they could take action to ensure that they did not contaminate later steps of an operation.

“More work needs to be done before we can say that all the elements required for fault-tolerant quantum computation are in place, but I do think this work shows that we are close,” says Daniel Gottesman, who works on quantum error correction at the Perimeter Institute in Waterloo, Ontario.

The elements still required are not trivial, though. The bit flips that Martinis and colleagues took on can be addressed using classical algorithms that work on a conventional computer. A trickier kind of error, where a quantum property of a qubit known as “phase” is altered by environmental noise, can only be tackled using more complex algorithms that exploit quantum effects. Austin Fowler, a quantum electronics engineer with Google, says the group is now working on that, and on demonstrating error checking on more than nine qubits.

Still, recent results from Martinis and others make Gottesman optimistic that the full set of error correction techniques is within reach. “I think there is a good chance we will see such a demonstration by someone, possibly the Martinis group, within the next few years,” he says.

Want to go ad free? No ad blockers needed.

Become an Insider
Already an Insider? Log in.

Uh oh–you've read all of your free articles for this month.

Insider Premium
$179.95/yr US PRICE

More from Intelligent Machines

Artificial intelligence and robots are transforming how we work and live.

Want more award-winning journalism? Subscribe to Insider Plus.
  • Insider Plus {! insider.prices.plus !}*

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus ad-free web experience, select discounts to partner offerings and MIT Technology Review events

    See details+

    What's Included

    Bimonthly magazine delivery and unlimited 24/7 access to MIT Technology Review’s website

    The Download: our daily newsletter of what's important in technology and innovation

    Access to the magazine PDF archive—thousands of articles going back to 1899 at your fingertips

    Special discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

/
You've read all of your free articles this month. This is your last free article this month. You've read of free articles this month. or  for unlimited online access.