Expectations are outpacing even the "really rapid progress" being made at laboratories around the world including in Australia. "We recognise that this is likely a multi-decades enterprise to really get to the finish line,” he said. The race looks exceedingly well worth running. Unlike traditional computers, which use discrete zeros and ones, quantum computing's bits – dubbed qubits – can be either a one, a zero or both at the same time. This property, called superposition, promises a massive increase in computing speeds, potentially solving our biggest challenges. These could range from tackling climate change to understanding the origins and fate of the cosmos, or "the Big Bang, Big Crunch", as Professor Hayden puts it. 'Early days' Loading

As if to highlight the pace of advances, the physics professor describes the late-1990s as "the early days" of his field, when "a lot of very sensible and otherwise open-minded scientists, said quantum computer will never work". Obstacles include the microscopic nature of the work - such as trying to control and write information on a single electron. Calculations can be thrown out by random fluctuations in the qubit, such as those from heat. So-called error correction research has lowered the fault rate to 1 in 10,000. Even so, the largest quantum computer - one now being tested by Google - is still only 72 qubits in size, while IBM has a 50-qubit one. “To reach the full promise of quantum computing, we need a one million-qubit device,” Professor Hayden said, adding that level may be achieved in the next generation of devices. "The stage that we’re at right now, the leading technologies – super conducting circuits – have a road map to get up to a few hundred, maybe 1000 qubits," he said.

"After that, they hit some pretty severe constraints," Professor Hayden said, adding "there’s a 30 per cent chance that something completely different comes along that might be the way to scale it up in the future”. 'Mt Everest of computing' That doesn't mean current devices won't be useful for very specialised applications. And even a "totally useless computation" could before long deliver an important achievement in the race by beating the world's most powerful super computer, he said. “That’s going to happen," Professor Hayden said. "That’s going to be a Mt Everest of computing.” Some of the milestones already achieved by the field will feature in Professor Hayden's talk at Sydney University.