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http://news.com.com/Wizardry+at+Har...ight/2100-11395_3-6157563.html?tag=ne.fd.mnbc
In 1999, Hau headed a team of scientists that slowed light, which travels a brisk 186,282 miles a second when unimpeded, to a leisurely 38 miles an hour by shining it into an exotic, ultracooled cloud of sodium atoms. At temperatures a fraction of a degree above absolute zero, the atoms coalesce into a single quantum mechanical entity known as a Bose-Einstein condensate. Shining a laser on the cloud tunes its optical properties so that it becomes molasses when a second light pulse enters it.
Then, in 2001, Hau and a second team of physicists, this one from the Harvard-Smithsonian Center for Astrophysics, brought light to a complete halt by slowly turning off the laser. The Bose-Einstein cloud turned opaque, trapping the light pulse inside. When the laser was turned back on, the trapped light pulse flew out.
The latest results add an additional twist: transporting the pulse to a second Bose-Einstein cloud and regenerating the light there.
"That's the sort of stuff we find really sexy in this business," said Eric A. Cornell, a senior scientist at the National Institute of Standards and Technology.
In the new Harvard experiment, when the initial pulse slammed into the first Bose-Einstein cloud, the collision caused 50,000 to 100,000 of the sodium atoms to start spinning, almost like small tops, and pushed this small clump forward at less than a mile an hour.
Hau described the clump of atoms as a "metacopy" of the light pulse. Although it consisted of sodium atoms instead of particles of light, it exactly captured the characteristics of the light pulse.
The clump floated out from the rest of the cloud, traveled about two-tenths of a millimeter and burrowed into a second Bose-Einstein cloud. When a laser was shined on the second cloud, the atom clump transformed into a new pulse of light identical to the original pulse.
It was refinements to the 2001 experimental technique that extended the time the particles maintain quantum collective behavior. This allowed the clump to reach the second cloud.
In 1999, Hau headed a team of scientists that slowed light, which travels a brisk 186,282 miles a second when unimpeded, to a leisurely 38 miles an hour by shining it into an exotic, ultracooled cloud of sodium atoms. At temperatures a fraction of a degree above absolute zero, the atoms coalesce into a single quantum mechanical entity known as a Bose-Einstein condensate. Shining a laser on the cloud tunes its optical properties so that it becomes molasses when a second light pulse enters it.
Then, in 2001, Hau and a second team of physicists, this one from the Harvard-Smithsonian Center for Astrophysics, brought light to a complete halt by slowly turning off the laser. The Bose-Einstein cloud turned opaque, trapping the light pulse inside. When the laser was turned back on, the trapped light pulse flew out.
The latest results add an additional twist: transporting the pulse to a second Bose-Einstein cloud and regenerating the light there.
"That's the sort of stuff we find really sexy in this business," said Eric A. Cornell, a senior scientist at the National Institute of Standards and Technology.
In the new Harvard experiment, when the initial pulse slammed into the first Bose-Einstein cloud, the collision caused 50,000 to 100,000 of the sodium atoms to start spinning, almost like small tops, and pushed this small clump forward at less than a mile an hour.
Hau described the clump of atoms as a "metacopy" of the light pulse. Although it consisted of sodium atoms instead of particles of light, it exactly captured the characteristics of the light pulse.
The clump floated out from the rest of the cloud, traveled about two-tenths of a millimeter and burrowed into a second Bose-Einstein cloud. When a laser was shined on the second cloud, the atom clump transformed into a new pulse of light identical to the original pulse.
It was refinements to the 2001 experimental technique that extended the time the particles maintain quantum collective behavior. This allowed the clump to reach the second cloud.
