A quantum computer is a device for computation that makes direct use of distinctively quantum mechanicalphenomena, such as superposition and entanglement, to perform operations on data. In a classical (or conventional) computer, information is stored as bits; in a quantum computer, it is stored as qubits (quantum binary digits).
The basic principle of quantum computation is that the quantum
properties can be used to represent and structure data, and that
quantum mechanisms can be devised and built to perform operations with this data.
Although quantum computing is still in its infancy, experiments have
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, and 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. If large-scale quantum computers can be built, they will be able to
solve certain problems much faster than any of our current classical
computers (for example Shor's algorithm). Quantum computers are different from other computers such as DNA computers and traditional computers based on transistors. Some computing architectures such as optical computers[3] may use classical superposition of electromagnetic waves. Without some specifically quantum mechanical resources such as entanglement, it is conjectured that an exponential advantage over classical computers is not possible
The massive amount of processing power generated by computer
manufacturers has not yet been able to quench our thirst for speed and
computing capacity. In 1947, American computer engineer Howard Aiken said that just six electronic digital computerswould satisfy the computing needs of the United States. Others have
made similar errant predictions about the amount of computing power
that would support our growing technological needs. Of course, Aiken
didn't count on the large amounts of data generated by scientific
research, the proliferation of personal computers or the emergence of the Internet, which have only fueled our need for more, more and more computing power.
Will we ever have the amount of computing power we need or want? If, as Moore's Law states, the number of transistors on a microprocessorcontinues to double every 18 months, the year 2020 or 2030 will find
the circuits on a microprocessor measured on an atomic scale. And the
logical next step will be to create quantum computers, which will harness the power of atoms and molecules to perform memoryand processing tasks. Quantum computers have the potential to perform
certain calculations significantly faster than any silicon-based
computer.
Scientists have already built basic quantum computers that can
perform certain calculations; but a practical quantum computer is still
years away. In this article, you'll learn what a quantum computer is
and just what it'll be used for in the next era of computing.
You don't have to go back too far to find the origins of
quantum computing. While computers have been around for the majority of
the
20th century, quantum computing was first theorized less than 30 years
ago, by a physicist at the Argonne National Laboratory. Paul Benioffis credited with first applying quantum theory to computers in 1981.
Benioff theorized about creating a quantum Turing machine. Most digital
computers, like the one you are using to read this article, are based
on the Turing Theory. Learn what this is in the next section. |
