Friday, July 10, 2009
An optical lattice (blue) uses lasers to isolate and control rubidium atoms (red), with polarized light used as information "bits" in future quantum computers.
The National Institute of Standards and Technology (NIST) is banking on quantum computers to cash in on solving "super" problems that are intractable today--such as creating uncrackable encryption codes for national security. By encoding quantum bits, or qubits, that represent both ones and zeroes simultaneously--a technique called superposition--quantum computers bypass all the sequential steps needed to sift data the way normal computers do. Look for NIST to announced a working quantum computer within three years. R.C.J.
Quantum computers have inched closer to reality after the National Institute of Standards and Technology (NIST) researchers demonstrated the ability to read and write individual quantum bits using a combination of microwaves and polarized lasers. The technical challenge is controlling a quantum computer's processing steps without disturbing the delicate superposition state that makes the qubits so useful. The situation is especially troublesome for adjacent qubits, since reading or writing one qubit often disturbs the state of adjacent ones.
NIST researchers claim to have found an technique that solves the problem by first selecting the atom with the pinpoint accuracy of a polarized laser beam. The technique allows individual qubits to be read and written with microwaves that do not disturb the state of adjacent qubits. The researchers said this week they are now attempting to develop their prototype into a working quantum computer.
Posted by R. Colin Johnson at 10:56 AM