Book contents
- Frontmatter
- Contents
- Introduction
- Part I Quantum information
- Part II Quantum computation
- 7 Principles of quantum computing
- 8 Elementary quantum algorithms
- 9 More advanced quantum algorithms
- 10 Trapped atoms and ions
- 11 Nuclear magnetic resonance
- 12 Large-scale quantum computers
- Part III Quantum communication
- Appendix: Quantum mechanics
- References
- Index
7 - Principles of quantum computing
from Part II - Quantum computation
Published online by Cambridge University Press: 05 August 2012
- Frontmatter
- Contents
- Introduction
- Part I Quantum information
- Part II Quantum computation
- 7 Principles of quantum computing
- 8 Elementary quantum algorithms
- 9 More advanced quantum algorithms
- 10 Trapped atoms and ions
- 11 Nuclear magnetic resonance
- 12 Large-scale quantum computers
- Part III Quantum communication
- Appendix: Quantum mechanics
- References
- Index
Summary
In Part II of this book we show how computations can be implemented using quantum systems. As we will see, the differences between bits and qubits, briefly outlined in Part I, lead to some important consequences for quantum computing. We begin with a brief introduction to the fundamental principles underlying quantum computing: specific implementations will be considered in later chapters.
Reversible computing
While quantum computation in its modern form is still a relatively young discipline, researchers have been interested in the relationship between quantum mechanics and computing for a long time. Early workers were not interested in the ideas of quantum parallelism, which will be explored in the next section, but rather in the question of whether explicitly quantum mechanical systems could be used to implement classical computations. In addition to its intrinsic interest, there are two technological reasons why this might be considered an important question.
The first reason is a direct consequence of Moore's laws. After the development of integrated circuits, computing technology began its headlong dash down the twin roads of ever-faster and ever-smaller devices. These two phenomena are closely related: as computing devices must communicate within themselves, and as the speed of information transfer cannot exceed the speed of light, faster computers must indeed be smaller. There is, however, a limit to this process, defined by the atomic scale: once the size of individual transistors becomes comparable with that of atoms, the old-fashioned approach of micro-electronics becomes completely untenable.
- Type
- Chapter
- Information
- Quantum Information, Computation and Communication , pp. 67 - 72Publisher: Cambridge University PressPrint publication year: 2012