Quantum computer

A quantum computer is any device for computation that makes direct use of distinctively quantum mechanical phenomena, such as superposition and entanglement, to perform operations on data. In a classical (or conventional) computer, the amount of data is measured by bits; in a quantum computer, it is measured by qubits. The basic principle of quantum computation is that the quantum properties of particles can be used to represent and structure data, and that devised quantum mechanisms can be used to perform operations with this data. For a generally accessible overview of quantum computing, see Quantum Computing with Molecules, an article in Scientific American by Neil Gershenfeld and Isaac L. Chuang.

Related Topics:
Computation - Quantum mechanical - Superposition - Entanglement - Data - Qubit - Scientific American - Neil Gershenfeld

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Experiments have already been carried out in which quantum computational operations were executed on a very small number of qubits. Research in both theoretical and practical areas continues at a frantic pace; see Quantum Information Science and Technology Roadmap for a sense of where the research is heading. Many national government and military funding agencies support quantum computing research, to develop quantum computers for both civilian and national security purposes, such as cryptanalysis.

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See the Nature article in the references below reporting on work at IBM Almaden Research Center, where scientists implemented a seven qubit computing device that ran Shor's factorization algorithm.

Related Topics:
''Nature'' - IBM - Almaden Research Center - Shor's factorization algorithm

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It is widely believed that if large-scale quantum computers can be built, they will be able to solve certain problems faster than any classical computer. Quantum computers are different from classical computers such as DNA computers and computers based on transistors, even though these may ultimately use some kind of quantum mechanical effect (for example covalent bonds). Some computing architectures such as optical computers may use classical superposition of electromagnetic waves, but without some specifically quantum mechanical resource such as entanglement, they do not share the potential for computational speed-up of quantum computers.

Related Topics:
Computers - DNA computer - Transistor - Covalent bond - Optical computer - Entanglement

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