Google team promises 'quantum supremacy' by 2018
The leader of the Google research group focused on quantum computing, John Martinis, has announced that his team are to develop a chip that can outperform any conventional computer in performing complex mathematical operations by the end of 2017. The claim is conditional on successful tests of a six-qubit chip with the qubits arranged in a two-by-three matrix. The configuration is important: Google has already demonstrated a chip with nine qubits arranged in a line, but Martinis needs to show that it is possible to place qubits side by side without cross-interference before he can build a "quantum supremacy" chip, which will comprise a seven-by-seven grid of 49 qubits.
“We think we’re ready to do this experiment. It’s something we can do now,” says Martinis.

One reason for his confidence is that Google’s roughly 25-strong group has made a new quantum chip that tests out key design features needed to make a device for that head-to-head contest.

Quantum chips represent digital bits of data using qubits, devices that can shortcut through some tough calculations by exploiting the counterintuitive physics of quantum mechanics. Researchers have so far demonstrated quantum computing with only small groups of qubits, though. Google has released results from a chip that has nine qubits arranged in a line, but Martinis says he’ll need a grid of 49 qubits for his quantum supremacy experiment.

Google’s latest chip has only six qubits, but they are arranged in a two-by-three configuration that Martinis says shows the company’s technology still works when qubits are nestled side by side, as they will be in larger devices.

Google’s chip ready for testing. Google

The six-qubit chip is also a test of a manufacturing method in which the qubits and the conventional wiring that controls them are made on separate chips later “bump bonded” together. That approach, a major focus of Google’s team since it was established just over two years ago, is intended to eliminate the extra control lines needed in a larger chip, which can interfere with how qubits function.

“That process is all working,” says Martinis. “Now we’re ready to kind of move fast.” Designs for devices with 30 to 50 qubits are already in progress, he says. He briefly flashed up images of the six-qubit chip at the recent IEEE TechIgnite conference in Burlingame, California, but his group has yet to formally disclose technical details.

Martinis joined Google in late 2014 from the University of California, Santa Barbara, where he remains a professor today (see “Google Launches Effort to Build Its Own Quantum Computer”). His team is one of several industrial research groups recently formed or expanded thanks to growing signs that the technology behind quantum computing is becoming more tractable. The race to develop quantum processors includes Intel, Microsoft, IBM, and even startups (see “10 Breakthrough Technologies 2017: Practical Quantum Computers”).

Simon Gustavsson, a principal investigator in a quantum computing research group at MIT, says that Google is one of the leaders. “It’s pretty comparable between Google and IBM,” he says.