Quantum Computing: A New Era of Computing Technology

Mazhar Ali Dootio
My this article is published in online newspaper The Sindh Times

http://www.thesindhtimes.com/blogs/quantum-computing-new-era-computing-technology/

The development of computing system is really a great invention of the world. Because majority of the discoveries are done due to computer technology. Therefore, computing technology has brought a revolution in developing a world technologically as well as converting it into a global village. Now a day, people are very much happy with the current computer systems and information technological infrastructures. The scientific work is growing day to day because of latest computing system. The emergence of new technology called quantum computing, has opened new doors of development and high speeds processors. A quantum computer exploits properties of quantum physics to perform certain types of calculations more efficiently than any classical computer. Now traditional computing systems will be like abacus for whole world because quantum computing system will replace the traditional computers. Quantum computing is computing which is developed on basis of quantum-mechanical phenomena, such as Superposition and entanglement. A quantum computer is a device that performs quantum computing. Such a computer is different from binary digital electronic computers based on transistors. Whereas common digital computing requires that the data be encoded into binary digits, usually called bits, each of which is always in one of two definite states such as 0 or 1. Quantum computation uses quantum bits or qubits, which can be in superposition of states. A quantum Turing Machine is a theoretical model of such a computer, and is also known as the universal quantum computer. Quantum computing is the area of study focused on developing computer technology based on the principles of quantum theory, which explains the nature and behaviour of energy and matter on the quantum level. Development of a quantum computer would mark a leap forward in computing capability far greater than that from the Abacus to a modern day Super-Computers. The quantum computer, following the laws of quantum physics, would gain enormous processing power through the ability to be in multiple states, and to perform tasks using all possible permutations simultaneously. Current centers of research in quantum computing include MIT, IBM, Oxford University, and the Los Alamos National Laboratory. Quantum computers could one day provide breakthroughs in many disciplines, including materials and drug discovery, the optimization of complex systems, and artificial intelligence. But to realize those breakthroughs, and to make quantum computers widely use able and accessible, we need to re imagine information processing and the machines that do it.

The essential elements of quantum computing originated with Paul Benioff, working at Argonne National Labs, in 1981. He theorized a classical computer operating with some quantum mechanical principles. But it is generally accepted that David Deutsch of Oxford University provided the critical impetus for quantum computing research. In 1984, he was at a computation theory conference and began to wonder about the possibility of designing a computer that was based exclusively on quantum rules, then published his breakthrough paper a few months later. With this, the race began to exploit his ideas. However, before we probe into what he started, it is beneficial to have a look at the background of the quantum world.

The development of actual quantum computers is still in its infancy even in the year 2018, but experiments have been carried out in which quantum computational operations were executed on a very small number of quantum bits. Both practical and theoretical research continues, and many national governments and military agencies are funding quantum computing research in additional effort to develop quantum computers for civilian, business, trade, environmental and national security purposes, such as crypt-analysis. A small 20-QUBIT quantum computer exists and is available for experiments via the IBM Quantum Experience project. D-Wave Systems has been developing their own version of a quantum computer that uses annealing.

Large-scale quantum computers would theoretically be able to solve certain problems much more quickly than any classical computers that use even the best currently known algorithms

A Comparison of Classical and Quantum Computing

Classical computing depend on its ultimate level, on principles expressed by Boolean algebra, operating with a logic gate principle. Data must be processed in an exclusive binary state at any point in time - that is, either 0 (off / false) or 1 (on / true). The millions of transistors and capacitors at the heart of computers can only be in one state at any point. While the time that each transistor or capacitor need be either in 0 or 1 before switching states is now measurable in billionths of a second, there is still a limit as to how quickly these devices can be made to switch state. As we progress to smaller and faster circuits, we begin to reach the physical limits of materials and the threshold for classical laws of physics to apply. Beyond this, the quantum world takes over, which opens a potential as great as the challenges that are presented.

The Quantum computer, by contrast, can work with a two-mode logic gate: XOR and a mode called QO1 (the ability to change 0 into a superposition of 0 and 1, a logic gate which cannot exist in classical computing). In a quantum computer, a number of elemental particles such as electrons or photons can be used, with either their charge or polarization acting as a representation of 0 and /or 1. Each of these particles is known as a quantum bit, or qubit, the nature and behaviour of these particles form the basis of quantum computing. The two most relevant aspects of quantum physics are the principles of superposition and entanglement.

Superposition

Think of a qubit as an electron in a magnetic field. The electron's spin may be either in alignment with the field, which is known as a spin-up state, or opposite to the field, which is known as a spin-down state. Changing the electron's spin from one state to another is achieved by using a pulse of energy, such as from a laser - let's say that we use 1 unit of laser energy. But what if we only use half a unit of laser energy and completely isolate the particle from all external influences? According to quantum law, the particle then enters a superposition of states, in which it behaves as if it were in both states simultaneously. Each qubit utilized could take a superposition of both 0 and 1. Thus, the number of computations that a quantum computer could undertake is 2^n, where n is the number of qubits used. A quantum computer comprised of 500 qubits would have a potential to do 2^500 calculations in a single step. This is an awesome number - 2^500 is infinitely more atoms than there are in the known universe This is true parallel processing - classical computers today, even so called parallel processors, still only truly do one thing at a time: there are just two or more of them doing it. But how will these particles interact with each other? They would do so via quantum entanglement.

Entanglement Particles such as photons, electrons, or qubits that have interacted at some point retain a type of connection and can be entangled with each other in pairs, in a process known as correlation . Knowing the spin state of one entangled particle - up or down - allows one to know that the spin of its mate is in the opposite direction. Even more amazing is the knowledge that, due to the phenomenon of superposition, the measured particle has no single spin direction before being measured, but is simultaneously in both a spin-up and spin-down state. The spin state of the particle being measured is decided at the time of measurement and communicated to the correlated particle, which simultaneously assumes the opposite spin direction to that of the measured particle. This is a real phenomenon (Einstein called it "spooky action at a distance"), the mechanism of which cannot, as yet, be explained by any theory - it simply must be taken as given. Quantum entanglement allows qubits that are separated by incredible distances to interact with each other instantaneously (not limited to the speed of light). No matter how great the distance between the correlated particles, they will remain entangled as long as they are isolated.

Taken together, quantum superposition and entanglement create an enormously enhanced computing power. Where a 2-bit register in an ordinary computer can store only one of four binary configurations (00, 01, 10, or 11) at any given time, a 2-qubit register in a quantum computer can store all four numbers simultaneously, because each qubit represents two values. If more qubits are added, the increased capacity is expanded exponentially.

IBM Q is an industry first initiative to build universal quantum computers for business and science. IBM Q quantum devices are accessed using Qiskit, a modular, open-source programming framework. A worldwide network of Fortune 500 companies, academic institutions, and start-ups use IBM Q technology and collaborate with IBM Research to advance quantum computing. IBM has several real quantum devices and simulators available for use through the cloud. These devices are accessed and used through Qiskit, and open source quantum software development kit, and IBM Q Experience, which offers a virtual interface for coding a quantum computer. IBM is rapidly driving scientific advancements and discovery in improving the functionality of quantum computers and realizing quantum’s potential to solve some of the today’s unsolvable problems in areas such as chemistry, machine learning and optimization. The IBM Q Experience Community brings together researchers and quantum enthusiasts to share, connect and collaborate.

D-Wave system’s flagship product, the 2000 qubit D-Wave 2000Q quantum computer, is the most advanced quantum computer in the world. It is based on a novel type of superconducting processor that uses quantum mechanics to massively accelerate computation. It is best suited to tackling complex optimization problems that exist across many domains such as: Optimization, Machine learning, Sampling / Monte Carlo, Pattern recognition and anomaly detection, Cyber security, Image analysis, Financial analysis, Software / hardware verification and validation and Bioinformatics / cancer research.

Quantum computing is latest and emerging development of modern era. It will change the structure and style of current computing systems as well as world. What we imagine our future computer world will be provided by quantum computing. Future research on quantum computing may change even the physical structure of world by virtualization / virtual reality. Therefore, the next wave of computing, which will supercharge artificial intelligence and cryptography, involves going quantum computing.