Only God can count that fast — the world of quantum computing
The progress seen in IT over the last few years is truly mind-boggling. And yet the computational power of classical computers appears to be limited. Therefore everyone whose sights are set on boundless technological advances turns their attention to a technology promising to deliver another big breakthrough — quantum computing.
Although they have been talked about since the 1980s, it has only become clear in the last few years that of quantum computers are definitely on the rise. The hype around them has been growing ever stronger. Experts have gone as far as to concede that we are about to witness a computational speedup of unprecedented proportions.
How can that be? Today’s processors comprise billions of transistors the size of a few nanometers packed into a very small space. According to Moore’s law, the number of transistors fit into a microprocessor doubles roughly every two years. Unfortunately, increases in the processing power of processors have been nearing a plateau. We are approaching the technological limits of how many transistors can be “jam-packed” into such a small space. The borderline that cannot physically be crossed is a transistor the size of a single atom with a single electron used to toggle between the states of 0 and 1.
This year may well bring a breakthrough in the development of the quantum technology. What makes the latest prediction significantly more likely to come true is the recently massive involvement in research in the field by Microsoft and Google.
Atos, a company I am pleased to represent, has also invested considerable amounts of energy over the last few months into bringing us closer to constructing a superfast quantum computer.
Picture 1: Quantum computer processor qubit.jpg: Qubit placed in the center of a processor
The source of the big advantages of quantum computing
The simplest way to explain this is to compare quantum and classical computers. The familiar conventional device we know from our daily work relies on the basic information units called bits for all of its operations. These, however, can only represent either of the two states of 0 or 1.
The talk in quantum computing is of using intermediate states that liberate us from the bounds of the two opposing values. The qubit (or quantum bite), which is what the information units used by quantum devices are called, have the capacity to assume the values of 0 and 1 simultaneously. In fact, they can assume an infinite number of states between 0 and 1 achieving what is referred to as the superposition. Only when the value of a qubit is observed does it ever assume either of the two basic states of 0 or 1.
This may seem like a minor difference but a qubit remaining in a superposition can perform multiple tasks at the same time. We are helped here by the operation of two fundamental laws of quantum physics. Physically, a qubit can be represented by any quantum set to two different basic states such as an electron or atom spin, two energy levels in an atom or two levels of photon polarization: vertical and horizontal.
While in a classical computer, a bit holds two values, two bits holds four values, and so forth, two qubits hold not one but four values at any given time while 16 qubits may hold as many as 256 values simultaneously. Therefore, with every qubit added, the number of possibilities increases by a factor of two. The direct consequence of this is that, unlike a conventional machine, a quantum computer can perform multiple operations simultaneously.
Put more precisely: the above principle allows a quantum machine to process enormous amounts of data within an incredibly short time. Image a volume of data so big it would take millions of years to process by means of a classical computer.
However, this completely unthinkable task becomes quite workable with the use of a quantum machine. The device can process data hundreds of thousands, and ultimately, millions of times faster than machines made up of sophisticated silicon components! An ideal application for such a computer would be to sift through and recognize objects in an enormous collections of photographs. They would also be perfect for big number processing, encryption and code breaking. By resorting to mathematical data, the difference in capacity between quantum and conventional computers can theoretically amount to an astounding 1:18 000 000 000 000 000 000 times!
Picture 2: Quantum computer funnel.jpg: Plates distributed cylindrically in a quantum computer tunnel
Deep freeze and full isolation
The most credit for practical applications in the field can be ascribed to the Canadian tech company D–Wave. Its clients include various institutions ranging from government agencies to NASA, and for-profit corporations, such as Google. It is D-Wave that engineered the world’s first machine referred to as a quantum computer, also named D-Wave.
A far more advanced machine is the D-Wave 2X™ System. Its processor generates no heat and operates at temperatures of 0.015 degrees Kelvin (-273°C), which is 180 times colder than interstellar space! The processor’s environment is a vacuum with pressures 10 billion times lower than atmospheric pressure!
Qubits must be fully isolated from the environment as they are highly sensitive and easily damaged by e.g. changes in outdoor temperature, outdoor radiation, light or collisions with air molecules. That is why vacuum, super low temperatures and a fully shielded environment are necessary.
Although news about a device that deserves to be called a quantum computer has been released and denied many times already, the D-Wave 2X™ System brings us a step closer to producing a machine for which nothing is impossible. The D-Wave was immediately put to work on machine teaching, artificial intelligence and solving well-known biology problems such as protein twisting. However, note that over the last few years, a number of skeptics and experts have been passionately challenging the claims that are electrifying journalists and business people.
Picture 3: Quantum computer processor mounted.jpg: Processor mounted at the end of a tower with heat exchangers and circuit control units
Perhaps it is science fiction
To shed light on just how interesting and controversial quantum computing really is, allow me to provide examples of some of the extreme reactions from the IT community. A Google employee has recently claimed that the quantum computer D-Wave solved, within 1 second, a problem that a standard machine would supposedly need 10 000 years to complete! On the other hand, many opinions resemble that of the physicist Matthias Toyer. When, in a special test three years ago, the D-Wave2 was said to have solved a problem assigned to it 3600 times faster than a classical computer, Toyer questioned the result pointing out the lack of hard evidence to prove such efficiency. The confusion that arose in the field can best be illustrated by a quote from an employee of the National Institute of Standards and Technology in the USA, David Wineland, who said: “I’m optimistic [we’ll succeed] in the long term, but what ‘long-term means’ I don’t know”.
Perhaps we should give credence to the opinions of IBM experts who believe it will take at least a dozen years for such wonders of technology to come into practical use. Their view is that while such devices will inevitably be designed for research institutes and laboratories, there is little hope of them every coming to average users. All things considered, it is difficult today to make predictions with any degree of certainty.
What is in it for us?
A quantum computer requires a control system (an equivalent of an operating system), algorithms that allow one to make quantum calculations and proper calculation software.
The development of quantum algorithms is very difficult as they need to rely on the principles of quantum mechanics. The algorithms followed by quantum computers rely on the rules of probability. What this means is that by running the same algorithm on a quantum computer twice, one may get completely different results as the process itself is randomized. To put it simply, to produce reliable calculation results one has to factor in the laws of probability.
This sounds like a highly complex process. Unfortunately, it is. Quantum computers are suited for very specialized and specific calculations as well as algorithms to help harness all of their powers. In other words, quantum computers will not appear on every desk or in every home. Using them there make no sense.
Regardless of how much time is needed to generate a given result from the work of an algorithm, we can imagine, even today, a situation in which a quantum machine is required to solve a specific problem. Assume, for instance, that we want to process massive amounts of medical data to find a cure of cancer. A quantum computer using adequate algorithms could bring us closer to developing an effective formula. Neither the human brain nor any classical computer could possibly interpret all such data without errors or without overlooking significant information.
Quantum technologies have the potential to powerfully influence astronomy, mathematics, physics and other fields. Quantum computers can instantaneously sift through huge amounts of data. This, in fact, may be the main reason why special agencies and Google invest so much in the technology. Quantum computers may make ideal code breaking tools. They can make quick work of cracking systems relying on the RSA method, which protects Internet browser lines and lines used for mobile and online banking. Quantum computing is declared to be the first technology threaten the cryptographic algorithms of the blockchain and cryptocurrencies such as the bitcoin.
Evidently, the technology is not all advantages. There is definitely a dark side to it as well. Will we be able to continue to rely on encryption as we know it today? Will we be able to protect our critical and previously unbreakable codes from being cracked? What will the world be like if any bit of information is available within a blink of an eye? Instantaneously, indeed, but not for all as access will be limited to those who possess quantum computers and quantum computing technology.
Picture 4: What are the quantum computers?; University of Cambridge