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Quantum supremacy, the year's biggest computer-tech story

By Anand Parthasarathy
December 20 2019: For almost a decade, scientists have been touting the revolutionary nature of the technology – and the unimaginably high speeds of computation that it offers. Yet research worldwide has remained just  that,  with  no visibility  of practical realization.  End October changed all that.
In an announcement by its India-born CEO Sundar Pichai,   Google  claimed that it’s team of researchers had achieved a big breakthrough in quantum computing known as quantum supremacy. The term meant that they had used a quantum computer to solve a problem that would take a classical computer an impractically long amount of time.  They had successfully performed a test computation in just 200 seconds that would have taken the best known algorithms in the most powerful supercomputers thousands of years to accomplish, Pichai reported.
As the world of high performance computing struggled to grasp the magnitude of this claimed achievement, the journal Nature published a paper  jointly authored by 77 engineers titled “Quantum supremacy using a programmable superconducting processor”, laying out the details of the computation performed by their quantum computer, with a explicit claim that the best supercomputer today using conventional technology would take 10,000 years to complete the same  calculation.  To do this computation, the Google team  designed a quantum processor named ‘Sycamore’ which consists of a two-dimensional array of 54  qubits – the quantum equivalent of the bits – ones and zeroes  -- that we are used to in all digital calculations.  ( see Image of the Day: Bits versus Qubits).
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The fuller version of this article appears in the December 2019
issue of the monthly journal, Science Reporter

http://nopr.niscair.res.in/handle/123456789/52697
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Pulses of microwaves cause the qubits to vibrate  and electromagnetic pulses at a different frequency cause the bit flips.  There is little to see outside – except a large  touch screen displaying  lines of  waveforms that correspond to the functions being performed on the qubits.
Another portion of the  screen displays  what is happening to each qubit,   as it oscillates between 1 and 0. Unlike the  digital ones and zeroes, these can be any value in between. This is known as  “superposition”   and is  at the core of  how qubits are infinitely superior to digital bits:   like a juggler in the circus,  juggling multiple balls, they can do more than on computation at a time…  resulting in the mind boggling computation speeds of  quantum computers.
The conditions  described above, under which quantum computers can work are so stringent, that  few organisations have been able to set them up.   Even researchers  may not be able to afford them. Which is why  according to Gartner,  a new service industry  may emerge: Quantum Computing as a Service ( QCaaS)  where academia  or industry  hoping  to harness quantum computers, can ‘pay by use”.
Google’s audacious  announcement that it has attained “quantum  supremacy”  has been received with skepticism in some quarters.  The term quantum supremacy is a concept which was originally coined in 2012, by Caltech professor of theoretical physics John Preskill  and means  a quantum computer  outperforms a classical computer  and does something a classical supercomputer cannot do today.
Every digital device  is a classical computer – from the first general purpose computer ENIAC, made in 1945, to your smart watch.  The fastest computer in the world today, is the'Summit' also called OCLF-4, developed by IBM and installed at the Oak Ridge National Laboratory  which in November 2018 performed 200 petaflops ( a peta flop is 1000 teraflops or 10 raised to the power 15 flops or floating point operations). 
IBM has a major programme in Quantum Computing running – and was the first to challenge Google on its claim of quantum supremacy. In a blog published after Google’s 'Nature' paper was published. It claimed that even by  a “conservative and worst-case estimate....an ideal simulation of the same task can be performed on a classical system in 2.5 days and with far greater fidelity”.   Ten thousand  years  versus  two-and-a-half  days?    No wonder  IBM suggested that Google’s claim should be taken with a “with a large dose of skepticism.”  The company goes on to suggest:
"By its strictest definition the goal has not been met......fundamentally, because quantum computers will never reign 'supreme' over classical computers, but will rather work in concert with them, since each have their unique strengths." It is also worth mentioning that while Google's Quantum computer demands extreme environmental conditions, it is economical when it comes to  real estate. The IBM Summit machine  occupies the space of 2 basketball courts.
The academic community is evenly divided between the positions  taken by Google and IBM -- and while  few actually  question the magnitude of the Google Quantum achievement,   some  are skeptical about its practical and ubiquitous  availability as a new tool of blazingly fast number crunching.
At Google though, there are no doubts:   It  has already signed up the first  few customers -- automobile giants  Volkswagen and Daimler  -- and the US Department of Energy  who  expect to be harnessing the Quantum Computer as early as next year, albeit  as a  cloud based service-on-demand.
The potential  applications of quantum computing straddle the gamut of applications: from  biochemistry and  drug discovery to  timely brain tumour detection in humans to  developing new non corrosive paints to predicting market instability. Common to all such applications is one factor:  Quantum Computers will perform  the required  calculations in  seconds rather than weeks.  How far are we from being able to address such tasks at quantum speeds? That is still a guessing game. But Google is very clear: "We are only one algorithm away from valuable near-term applications", its research paper claims.    Perhaps it is  finally time to say 'hello!'  to the brave new world of quantum computers.