Within the next couple of decades, experts think quantum computers will replace the ‘classical’ computers at our desks and revolutionise our lives.
By employing the odd effects of quantum physics, they’ll be capable of speeding up machine learning, solving climate change and discovering new drugs, it’s believed.
Now, Google claims it’s hit a major milestone in the quest to build such a device, by achieving ‘quantum supremacy’ – solving problems that no classical machine can.
The tech giant says it has created a quantum computer capable of instantly making calculations that would take even the fastest computer in existence today 47 years to do.
If this sounds familiar, Google said it achieved quantum supremacy back in 2019, although at the time the claim was questioned by opponents.
Google claims it’s achieved ‘quantum supremacy’ – using a quantum device to solve problems that no classical machine can. According to Google, the newest version of its Sycamore quantum processor runs 70 qubits, more than its earlier version of Sycamore that had 53 qubits (pictured)
Rival IBM pointed out that the task Google’s Sycamore quantum computer was able to perform was not a particularly difficult one and could technically be done by a classical machine albeit more slowly.
Four years on, Google researchers claim to have created a more powerful machine with capabilities beyond classical machines – in other words, quantum supremacy.
It remains unclear how much the quantum computer cost to develop, although MailOnline has contacted Google for further information.
‘Quantum computers hold the promise of executing tasks beyond the capability of classical computers,’ the team say in their paper, published on the arXiv pre-print server, yet to be peer reviewed.
‘We estimate the computational cost against improved classical methods and demonstrate that our experiment is beyond the capabilities of existing classical supercomputers.’
Quantum technology makes use of the spooky effects of quantum physics to vastly speed up information processing, which could lead to the most powerful computer on Earth.
Even the fastest computers that exist today – such as the Frontier supercomputer in Tennessee – don’t match the potential of quantum computers.
These ‘conventional’ or ‘classical’ computers use the processing language of binary code, a language based on one of two states – zeroes or ones.
In the new paper, Google demonstrates quantum supremacy or quantum advantage. This graph compares performance of the 70-qubit quantum computer compared with the previous iteration (Sycamore-53) and the Chinese Zuchongzhi quantum computer
Even the fastest computers that exist today, such as the Frontier supercomputer in Tennessee (pictured), don’t match the potential of quantum computers
But quantum mechanics allows a unit of quantum information – a quantum bit or ‘qubit’ – to be in a state of zero, one, or both states simultaneously.
According to Google, the newest version of its Sycamore quantum processor runs 70 qubits, more than its earlier version of Sycamore that had 53 qubits.
A quantum processor with 70 qubits means that it can store and process 70 quantum bits of information – impossible for a classical computer however fast or slow it’s going.
To put this power increase in perspective, the team says Frontier would only take 6.18 seconds to match a calculation from Google’s 53-qubit computer, but would take 47.2 years to match its latest one.
Google researchers say they now have the ‘ultimate goal of demonstrating and verifying the beyond-classical performance for our 70-qubit device’.
IBM is yet to comment on Google’s new work, but Steve Brierley, chief executive of Cambridge-based quantum company Riverlane, told the Telegraph that Google’s new work is a ‘major milestone’.
‘The squabbling about whether we had reached, or indeed could reach, quantum supremacy is now resolved,’ he said.
IBM’s Q System One (pictured) is a quantum computer available to businesses and researchers. The IBM Q System One is a powerful quantum computer, but it is not yet powerful enough to achieve quantum supremacy
However, Sebastian Weidt, from the University of Sussex’s Ion Quantum Technology group, echoed much of the criticism from 2019 – that Google is yet to demonstrate solving a useful problem with quantum.
‘This is a very nice demonstration of quantum advantage,’ Weidt said.
‘While a great achievement academically, the algorithm used does not really have real world practical applications though.
‘We really must get to utility quantum computing – an era where quantum computers with many thousand qubits actually begin to deliver value to society in a way that classical computers never will be able to.’
Professor Winfried Hensinger, director of the Sussex Centre for Quantum Technologies, told MailOnline: ‘Google solved a particular academic problem which is hard to compute on a conventional computer.
‘Their most recent demonstration is yet another powerful demonstration that quantum computers are developing at steady pace.
‘The next important step will be to build quantum computer which can correct for the inherent errors within their operation.’
The University of Sussex is leading the UK’s charge to build a quantum computer, along with the likes of big tech firms including Google, IBM and Microsoft.
Ultimately, the aim is to build a ‘commercial’ quantum computer – one that could be purchased by members of the public.
As this is still a decade or two away at least, for now, firms are building ‘experimental’ quantum computers that are still in the research and development phase.
IBM has already created a quantum machine called Q System One, available for businesses and researchers to use.
After it was revealed in 2019, critics pointed out that it only had 20 qubits and was not powerful enough to achieve quantum supremacy.
