Did this slip between the cracks in holiday season or has it already been
discussed here ?
Udhay
>DEVICE COULD LEAD TO HACK-PROOF TRANSMISSIONS
>Researchers at the University of California at Santa Barbara have
>created a photon "turnstile" that releases one light particle at
>a time, marking a major advance in the field of quantum
>cryptography. Until now, lasers, which emit tens of thousands of
>photons at once, provided the most control over photons. The
>turnstile, described in today's issue of "Science," could lead to
>the development of a quantum encryption system by allowing
>physicists to transmit a stream of single photons that holds the
>key to an encrypted message. If an outsider tried to intercept
>the stream, the key would become scrambled because a single
>photon cannot be examined without changing its properties,
>according to the principles of quantum mechanics. The sender
>would be alerted to the interception and could stop the
>transmission. The UC-Santa Barbara team built the turnstile by
>placing "quantum dots," or crystals with groups of positive and
>negative atoms, on a semiconductor. The researchers pulsed the
>entire structure with a laser, causing the turnstile to emit a
>single photon.
>(USA Today, 22 December 2000)
--
((Udhay Shankar N)) ((udhay @ pobox.com)) ((www.digeratus.com))
God is silent. Now if we can only get Man to shut up.
