Quantum computer solves problem -- without running
Read the article! I still don't understand
it.
Hosten &
KwiatBy combining quantum
computation and quantum interrogation, scientists at the University of Illinois
at Urbana-Champaign have found an exotic way of determining an answer to an
algorithm – without ever running the
algorithm.Using an optical-based
quantum computer, a research team led by physicist Paul Kwiat has presented the
first demonstration of “counterfactual computation,” inferring
information about an answer, even though the computer did not
run.“It seems absolutely bizarre
that counterfactual computation – using information that is counter to
what must have actually happened – could find an answer without running
the entire quantum computer,” said Kwiat, ”but the nature of quantum
interrogation makes this amazing feat
possible.”Sometimes called
interaction-free measurement, quantum interrogation is a technique that makes
use of wave-particle duality (in this case, of photons) to search a region of
space without actually entering that region of
space.“In a sense, it is the
possibility that the algorithm could run which prevents the algorithm from
running,” Kwiat said. “That is at the heart of quantum interrogation
schemes, and to my mind, quantum mechanics doesn’t get any more mysterious
than
this.”Although
I still don’t understand everything these lads are talking about —
they surely look like they should be part of the DU Army.
Posted: Fri - February 24, 2006 at 06:10 AM