A new quantum information technology (QIT) could emerge in the future, based on current research in the fields of quantum information processing and communication1, 2, 3 (QIPC). In contrast to conventional IT, where quantum mechanics plays a support role in improving the building blocks, fundamental quantum phenomena play a central role in QIPC — information is stored, processed, and communicated according to the laws of quantum physics. This additional freedom could enable future QIT to perform tasks we will never achieve with ordinary IT. Today many people are familiar with at least the consequences of Moore’s Law — the fastest computer in the shops doubles in speed about every 18 months to two years. This exponential progress, first noted4 by Gordon Moore — cofounder and former CEO of Intel — in 1965, has continued ever since. But it cannot go on forever. Hurdles exist, for example: silicon will hit problems, with oxide thinness or track width5; new materials or even new paradigms, such as self-assembled nano-devices or molecular electronics, will be needed; lots of dollars will be required as Moore’s second law tells us that fabrication costs are also growing exponentially. However, even if the hurdles can be overcome, we will eventually run into nature.
A new quantum information technology (QIT) could emerge in the future, based on current research in the fields of quantum information processing and communication1, 2, 3 (QIPC). In contrast to conventional IT, where quantum mechanics plays a support role in improving the building blocks, fundamental quantum phenomena play a central role in QIPC — information is stored, processed, and communicated according to the laws of quantum physics. This additional freedom could enable future QIT to perform tasks we will never achieve with ordinary IT. Today many people are familiar with at least the consequences of Moore’s Law — the fastest computer in the shops doubles in speed about every 18 months to two years. This exponential progress, first noted4 by Gordon Moore — cofounder and former CEO of Intel — in 1965, has continued ever since. But it cannot go on forever. Hurdles exist, for example: silicon will hit problems, with oxide thinness or track width5; new materials or even new paradigms, such as self-assembled nano-devices or molecular electronics, will be needed; lots of dollars will be required as Moore’s second law tells us that fabrication costs are also growing exponentially. However, even if the hurdles can be overcome, we will eventually run into nature.
Quantum mini-toc
In a world overwhelmed by increasing amounts of data, finding new ways to store and process information has become a necessity. Conventional silicon-based electronics has experienced rapid and steady growth, thanks to the progressive miniaturization of its basic component, the transistor, but that trend cannot continue indefinitely.
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CREDIT: PHOTO: CURT SUPLEE AND EMILY EDWARDS, JOINT QUANTUM INSTITUTE AND UNIVERSITY OF MARYLAND; CHIP FABRICATION: SANDIA NATIONAL LABORATORIES WITH SUPPORT FROM THE INTELLIGENCE ADVANCED RESEARCH PROJECTS ACTIVITY
In conventional devices, information is stored and manipulated in binary form: The elementary components of these devices—the so-called bits—have two states, each of which encodes the binary 0 or 1. To move beyond the binary system, one can exploit the laws of quantum mechanics. A quantum-mechanical object with two energy levels at its disposal can occupy either of those two levels, but also an arbitrary combination (superposition) of the two, much like an electron in a two-slit experiment can go through both slits at once. This results in infinitely many quantum states that a single quantum bit, or qubit, can take; together with another strange property of quantum mechanics—entanglement—it allows for a much more powerful information platform than is possible with conventional components.
Quantum information processing (QIP) uses qubits as its basic information units. QIP has many facets, from quantum simulation, to cryptography, to quantum computation, which is expected to solve problems more complex than those within the capabilities of conventional computers. To be useful for QIP, a qubit needs to be both isolated from its environment and tightly controllable, which places stringent requirements on its physical realization. But this is only the first step; to build a quantum computer, for example, we must also have a scalable architecture and error correction that can be performed in parallel with computation; in addition, efficient quantum algorithms must exist for solving the problem at hand—a considerable theoretical challenge.
A number of qubit types have been proposed and experimentally realized that satisfy at least some of these criteria, and tremendous progress has been made over the past decade in improving the figures of merit, such as the coherence time. In this special section, four Reviews look into the future of QIP in some of its most promising physical realizations. On p. [1164][2], Monroe and Kim discuss the challenges of scaling trapped ion architectures to hundreds and thousands of qubits and beyond. Devoret and Schoelkopf (p. [1169][3]) speculate on the future of superconducting circuits, whereas Awschalom et al. (p. [1174][4]) focus on the many promising qubit flavors based on spins in semiconductors. Finally, Stern and Lindner (p. [1179][5]) lay out the prospects for quantum computation using the entirely different approach of topologically protected states.
The future of QIP appears bright in spite of the many remaining challenges. As a bonus, overcoming these challenges will probably also advance basic research.
[1]: pending:yes
[2]: /lookup/volpage/339/1164?iss=6124
[3]: /lookup/volpage/339/1169?iss=6124
[4]: /lookup/volpage/339/1174?iss=6124
[5]: /lookup/volpage/339/1179?iss=6124
The marriage of quantum physics and information technology has the potential to generate radically new information processing devices. Examples are quantum cryptosystems, which provide guaranteed secure communication, and quantum computers, which manipulate data quantum mechanically and could thus solve some problems currently intractable to conventional (classical) computation. This introductory chapter serves two purposes. Firstly, I discuss some of the basic aspects of quantum physics which underpin quantum information technology (QIT). These will be used (and in somes cases further expanded upon) in subsequent chapters. Secondly, and as a lead into the whole book, I outline some of the ideas of QIT and its possible uses. To appear as Chapter 1 of Introduction to Quantum Computation and Information, eds. H.-K. Lo, S. Popescu and T. P. Spiller, (World Scientific Press 1998), http://www.wspc.com.sg/. 1 1 Introduction Information technology (IT) can feed off quantum physic...
Information is physical: the laws which govern its encoding, processing and communication are those of its unavoidable physical embodyment. In today's computing, information obeys the laws of Newton's and Maxwell's classical physics: this assertion holds all the way from commercial computers down to their most abstract models, e.g. Turing machines and lambda-calculi. Today's computation is classical.Research in quantum information processing and communication (QIPC) was born some twenty years ago, as a child of two major scientific achievements of the 20th century, namely quantum physics and information sciences. The driving force of this interdisciplinary research is that of looking for the consequences of having information encoding, computation and communication obey the laws of quantum physics, i.e. the ultimate knowledge that we have, today, of the foreign world of elementary particles, as described by quantum mechanics. Breakthroughs in algorithmics, cryptography, information theory and abstract computational models have shown that this rerooting of information from classical to quantum has far reaching consequences, both quantitative and qualitative, and opens new avenues for research within the foundations of computer science.The aim of this tutorial is to give a survey of the principles, main results and long term perspectives of current research in QIPC, from a computer science point of view. No prior knowledge in quantum mechanics is required to follow this tutorial. There will be two parts:1 - Computation, the quantum way: quantum bits and quantum operations; two major quantum algorithms: quadratic speedup for unordered database search (Grover's algorithm), exponential speedup for integer factoring (Shor's algorithm);2 - Communication, the quantum way, and longer term perspectives: quantum state teleportation; a quantum cryptographic protocol for secret key distribution. Hot topics in QIPC research, state of the art in physical implementation of quantum computers.
Information is physical. Today’s information processing and communication are classical: they are based upon the laws of Newton’s and Maxwell’s classical physics. This assertion holds all the way, from commercial computers and networks, up to their most abstract models, e.g. Turing machines. Research in quantum information was born some twenty five years ago, with the encounter of two major scientific achievements of the 20th century, namely quantum physics and information sciences. A technological motivation for that is an extrapolation of Moore’s law which seems to indicate that the amount of matter needed for one bit will be reduced to one particle sometimes before year 2020. A deeper, scientific driving force of this interdisciplinary research is that of looking for the consequences of having computation and communication based directly upon the laws of quantum physics, i.e. our current ultimate knowledge of the world of elementary particles, as described by quantum mechanics. Breakthroughs in cryptography, communications, information theory and algorithmics have shown that this transplantation from classical to quantum has far reaching consequences, both quantitative and qualitative, and opens new avenues for research within the foundations of computer science and physics. The principles 388 and most striking results and hot topics of this promising way of encoding, processing and communicating information are briefly introduced in this chapter from a mostly computer science point of view, with detailed examples in algorithmics and in cryptography. At the end of the chapter, a short list of some significant articles, textbooks and reports on quantum information are suggested for further reading.
The amount of data produced and processed every day is increasing exponentially, and reaching unthinkable levels. This amount of data has to be stored and processed by something. While the conventional computers are reaching their limits in data storage and processing, and this dictates the need for a nano sized transistors.Quantum computers can provide genius solution for that issue. Quantum computing is an emerging interdisciplinary field in information technology. This technology acquired its name, because it is based on quantum physics. In this article we present a new perspectiveonthe progress in the research efforts on quantum computing technology and their likelihood to replace the conventional computers and change the way we manipulate data and information. Also we claim this might be the first article in the region tackling quantum technology.
The word 'quantum' comes from the Latin word quantus meaning 'how much'. Quantum computing is a fundamentally new mode of information processing that can be performed only by harnessing physical phenomena unique to quantum mechanics (especially quantum interference). Paul Benioff of the Argonne National Laboratory first applied quantum theory to computers in 1981 and David Deutsch of Oxford proposed quantum parallel computers in 1985, years before the realization of qubits in 1995. However, it may be well into the 21st century before we see quantum computing used at a commercial level for a variety of reasons discussed in this paper. The subject of quantum computing brings together ideas from classical information theory, computer science, and quantum physics. This paper discusses some of the current advances, applications, and chal-lenges of quantum computing as well as its impact on corporate computing and implications for management. It shows how quantum computing can be utilized to process and store information, as well as impact cryptography for perfectly secure communication, algorithmic searching, factorizing large numbers very rapidly, and simulating quantum-mechanical systems efficiently. A broad interdisciplinary effort will be needed if quantum com-puters are to fulfill their destiny as the world's fastest computing devices.