Quantum computers are a step closer after a breakthrough in ultra-pure silicon that will make systems more stable and errors less likely, a team of Australian and British researchers say.

Prototypes for quantum computing have been developed around the world over the years but more reliable systems are needed to unlock progress in medicines, climate technologies, cryptography and logistics.

According to researchers from the University of Melbourne and University of Manchester, their silicone-based process has the “perfect qualities” to overcome a critical barrier to quantum computing.

Even when operated in tranquil conditions at near absolute zero, existing quantum computers can maintain so-called “error-free coherence” for only a tiny fraction of a second.

Potentially, quantum computers could solve in hours or minutes some problems that would take conventional computers – or even supercomputers – centuries, according to Professor David Jamieson from the University of Melbourne.

“Others are experimenting with alternatives but we believe silicon is the leading candidate for quantum computer chips that will enable the enduring coherence required for reliable quantum calculations,” he said.

“The great news is to purify silicon to this level, we can now use a standard machine – an ion implanter – that you would find in any semiconductor fabrication lab, tuned to a specific configuration that we designed.”

The national science agency CSIRO has estimated that quantum computing in Australia has potential to create 10,000 jobs and $2.5 billion in annual revenue by 2040.

“Our research takes us significantly closer to realising this potential,” Prof Jamieson said.

University of Manchester co-supervisor Professor Richard Curry said ultra-pure silicon allowed the construction of high-performance qubit devices – a critical component required to pave the way towards scalable quantum computers.

“What we’ve been able to do is effectively create a critical ‘brick’ needed to construct a silicon-based quantum computer,” Prof Curry said.

“It’s a crucial step to making a technology that has the potential to be transformative for humankind.”

The research published on Tuesday in a scientific journal explained that the ability to create high-quality silicon qubits has been limited by the purity of the material used, which the breakthrough has “solved”.

But in a challenge for the federal government, this new technique is significantly different from the quantum computing technology it recently invested in.

Some $940 million is going to Californian-headquartered company PsiQuantum to set up a quantum computer in Brisbane.

Prof Jamieson questioned whether Australia should be investing so heavily in one quantum route instead of backing a diverse range of research.

PsiQuantum says its mission is to build the world’s first useful, large-scale quantum computer and it has the backing of the United States’ Defense Advanced Research Projects Agency to do so.

The private company is also working with the US Department of Energy on cooling systems to support quantum computing.

Australia’s $15 billion National Reconstruction Fund has a portion earmarked for critical technologies, with quantum also a priority under the AUKUS security relationship.

Industry Minister Ed Husic has been contacted for comment.

 

Marion Rae
(Australian Associated Press)