by Robert Hackett
September 20, 2019
from Fortune Website

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Italian summarized version






In what may be a huge milestone in computing, Google says it has achieved "quantum supremacy," an experimental demonstration of the superiority of a quantum computer over a traditional one.

The claim, made in a new scientific paper, is the most serious indication yet that the promise of quantum computers - an emerging but unproven type of machine - is becoming reality, including their potential to solve formerly ungraspable mathematical problems.

Essentially, Google purports to have pulled off a stunt on a quantum computer that no classical machine - not even the world's most powerful supercomputer - can replicate.

Fortune obtained a copy of Google's paper, which was posted to earlier this week before being taken down. The Financial Times first reported the news (fully published here).

A Google spokesperson declined to confirm the authenticity of the paper and its results. NASA did not respond immediately to a request for comment.

A source at Google familiar with the situation suggested, however, that NASA accidentally published the paper early, before its team's claims could be thoroughly vetted through scientific peer review, a process that could take anywhere from weeks to months.

If the paper holds up under the scrutiny of the scientific community, it will herald a watershed moment in quantum science.


Its central claim counters doubt that some unforeseen law of nature may prevent quantum computers from operating as hoped.

"Quantum speedup is achievable in a real-world system and is not precluded by any hidden physical laws," the Google researchers write.

Further, they predict that quantum computing power will "grow at a double exponential rate," besting even the exponential rate that defined Moore's Law, a trend that observed traditional computing power to double roughly every two years.




The experiment

The experiment described in the paper sampled randomly generated numbers produced through a specialized scenario involving quantum phenomena.


The researchers said they determined that their quantum computer beat regular computers at the task, which involved calculating the output of certain specialized circuits.

"While our processor takes about 200 seconds to sample one instance of the quantum circuit 1 million times, a state-of-the-art supercomputer would require approximately 10,000 years to perform the equivalent task," the researchers said.

Google's quantum computer, dubbed "Sycamore," contained 53-qubits, or "quantum bits," a measure of the machine's potential power.


The team scaled back from a 72-qubit device, dubbed "Bristlecone," it had previously designed. The researchers estimate that performing the same experiment on a Google Cloud server would take 50 trillion hours - too long to be feasible.


On the quantum processor, it took only 30 seconds, they said.

"Quantum processors based on superconducting qubits can now perform computations...beyond the reach of the fastest classical supercomputers available today," the researchers write.


"To our knowledge, this experiment marks the first computation that can only be performed on a quantum processor."




Businesses are hoping the advancement of quantum computers, by tech giants such as,

  • Google

  • IBM

  • Intel

  • startups such as Rigetti Computing,

...will lead to unprecedented scientific and technical breakthroughs in the coming years.


They're eyeing applications from new chemical reactions for the development of drugs, fertilizers, and batteries, to the improvement of optimization algorithms and mathematical modeling.

As exciting as Google's result is, other researchers caution against overhyping it, fearing that inflated expectations of imminent advances will lead to a popped bubble.

Dario Gil, head of IBM Research, advises against using quantum supremacy as a metric with which to measure progress in the field.

"The experiment and the 'supremacy' term will be misunderstood by nearly all," he told Fortune.

Gil described the experiment as a highly special case "laboratory experiment" that has "no practical applications."


He added,

"Quantum computers will never reign 'supreme' over classical computers, but will rather work in concert with them, since each have their unique strengths."

Jim Clarke, Intel Labs' director of quantum hardware, called Google's update "a notable mile marker."


He said that,

"a commercially viable quantum computer will require" many R&D advancements before becoming a reality.

"While development is still at mile one of this marathon, we strongly believe in the potential of this technology," Clarke added.

The Google team, which first wrote about their goal in a Nature article (Quantum Computational Supremacy) two years ago, appears to be more hopeful about the short-term prospects of its findings.

"As a result of these developments, quantum computing is transitioning from a research topic to a technology that unlocks new computational capabilities," the researchers write.

"We are only one creative algorithm away from valuable near-term applications."










Google Claims to Have Reached...

Quantum Supremacy
by Madhumita Murgia and Richard Waters
September 20, 2019

from FT Website








Researchers say

their quantum computer

has calculated an impossible problem

for ordinary machines...




Google claims to have built the first quantum computer that can carry out calculations beyond the ability of today's most powerful supercomputers, a landmark moment that has been hotly anticipated by researchers.

A paper by Google's researchers seen by the FT (Financial Times), that was briefly posted this week on a NASA website before being removed, claimed that their processor was able to perform a calculation in three minutes and 20 seconds that would take today's most advanced classical computer, known as Summit, approximately 10,000 years.

The researchers said this meant the "quantum supremacy", when quantum computers carry out calculations that had previously been impossible, had been achieved.

"This dramatic speed-up relative to all known classical algorithms provides an experimental realization of quantum supremacy on a computational task and heralds the advent of a much-anticipated computing paradigm," the authors wrote.

"To our knowledge, this experiment marks the first computation that can only be performed on a quantum processor."

The system can perform only a single, highly technical calculation, according to the researchers, and the use of quantum machines to solve practical problems is still years away...

But the Google researchers called it,

"a milestone towards full-scale quantum computing".

They also predicted that the power of quantum machines would expand at a "double exponential rate", compared to the exponential rate of Moore's Law, which has driven advances in silicon chips in the first era of computing.

While prototypes of so-called quantum computers do exist, developed by companies ranging from IBM to start-ups such as Rigetti Computing, they can only perform the same tasks classical computers can, albeit quicker.

Quantum computers, if they can be built at scale, will harness properties that extend beyond the limits of classical physics to offer exponential gains in computing power.




'Change the game'

A November 2018 report by the Boston Consulting Group (BCG) said they could,

"change the game in such fields as cryptography and chemistry (and thus material science, agriculture and pharmaceuticals) not to mention artificial intelligence and machine learning...  logistics, manufacturing, finance and energy".

Unlike the basic binary elements of classical computers, or bits, which represent either zeros or ones, quantum bits, or qubits, can represent both at the same time.


By stringing together qubits, the number of states they could represent rises exponentially, making it possible to compute millions of possibilities instantly.

Some researchers have warned against overhyping the quantum supremacy, arguing that it does not suggest that quantum machines will quickly overtake traditional computers and bring a revolution in computing.

Led by John Martinis, an experimental physicist from the University of California, Santa Barbara, Google first predicted it would reach quantum supremacy by the end of 2017 (Characterizing Quantum Supremacy in Near-Term Devices).


But the system it built, linking together 72 qubits, proved too difficult to control.

It eventually revamped the system to create a 53-qubit design it codenamed Sycamore. The system was given the task of proving that a random-number generator was truly random.


Though that job has little practical application, the Google researchers said that "other initial uses for this computational capability" included machine learning, materials science and chemistry.

"It's a significant milestone, and the first time that somebody has shown that quantum computers could outperform classical computers at all," said Steve Brierley, founder of quantum software start-up Riverlane, who has worked in the field for 20 years and is an adviser on quantum technologies to the UK government.


"It's an amazing achievement."

Google declined to comment...