A Strange Computer Promises Great Speed
http://www.nytimes.com/2013/03/22/t....html?nl=todaysheadlines&emc=edit_th_20130322
Lockheed Martin will make commercial use of quantum computing, which could solve some business and science problems millions of times faster than can be done today.
A powerful new type of computer that is about to be commercially deployed by a major American military contractor is taking computing into the strange, subatomic realm of quantum mechanics. In that infinitesimal neighborhood, common sense logic no longer seems to apply. A one can be a one, or it can be a one and a zero and everything in between — all at the same time.
Quantum computing relies on the fact that subatomic particles inhabit a range of states. Different relationships among the particles may coexist, as well. Those probable states can be narrowed to determine an optimal outcome among a near-infinitude of possibilities, which allows certain types of problems to be solved rapidly.
There are a variety of ways scientists create the conditions needed to achieve superposition as well as a second quantum state known as entanglement, which are both necessary for quantum computing. Researchers have suspended ions in magnetic fields, trapped photons or manipulated phosphorus atoms in silicon.
In the D-Wave system, a quantum computing processor, made from a lattice of tiny superconducting wires, is chilled close to absolute zero. It is then programmed by loading a set of mathematical equations into the lattice.
The processor then moves through a near-infinity of possibilities to determine the lowest energy required to form those relationships. That state, seen as the optimal outcome, is the answer.
While similar subatomic properties are used by plants to turn sunlight into photosynthetic energy in a few million-billionths of a second, critics of D-Wave’s method say it is not quantum computing at all, but a form of standard thermal behavior.