Australia researchers say find new way to build quantum computers

Researchers in Australia have found a new way to build quantum computers which they say would make them dramatically easier and cheaper to produce at scale.

Quantum computers promise to harness the strange ability of subatomic particles to exist in more than one state at a time to solve problems that are too complex or time-consuming for existing computers.

Google, IBM and other technology companies are all developing quantum computers, using a range of approaches.

The team from the University of New South Wales say they have invented a new chip design based on a new type of quantum bit, the basic unit of information in a quantum computer, known as a qubit.

The new design would allow for a silicon quantum processor to overcome two limitations of existing designs: the need for atoms to be placed precisely, and allowing them to be placed further apart and still be coupled.

Crucially, says project leader Andrea Mello, this so-called "flip-flop qubit" means the chips can be produced using the same device technology as existing computer chips.

"This makes the building of a quantum computer much more feasible, since it is based on the same manufacturing technology as today's computer industry," Mello said.

That would allow chips for quantum computers to be mass-manufactured, a goal that has so far eluded other researchers.

IBM's quantum computer in the United States has 16 qubits, meaning it can only perform basic calculations. Google's computer has nine qubits.

A desktop computer runs at gigaflops. The world’s fastest supercomputer, China’s Sunway TaihuLight, runs at 93 petaflops, but relies on 10 million processing cores and uses massive amounts of energy.

In theory, even a small 30-qubit universal quantum computer could run at the equivalent of a classic computer operating at 10 teraflops.

The researchers' paper will be published in Nature Communications.

Laszlo Kish, a professor at Texas A&M University, said it was too early to say if the research was a breakthrough "but it may be a step in the proper direction" in solving some of the key obstacles to quantum computing.

The university has set up a company, Silicon Quantum Computing Pty Ltd, with investments from Telstra, Australia’s Commonwealth Bank and the Australian and New South Wales governments.

The A$83 million company plans to build a 10-qubit prototype silicon quantum integrated circuit – the first step in building the world’s first quantum computer in silicon - by 2022.