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Folks,
Check this out!
Source:
http://www.newsfactor.com/perl/story/21776.html
Check this out!
Source:
http://www.newsfactor.com/perl/story/21776.html
Using a discarded Apple Latest News about Apple hard drive from the mid 1990's, Cal Tech researchers have fabricated a mirror that reflects atoms instead of light.
The "atomic mirror" ultimately may help engineers create atomic lasers, ushering in new telecommunications Latest News about Telecommunication technologies based on atoms rather than photons, and atomic -- not electronic -- signals.
Mere Mirror?
"An atom mirror is a device that reflects impinging atoms in an analogous manner to the way a regular optical mirror reflects an incoming light beam," said Cal Tech quantum-optics researcher Benjamin Lev. "The difference between the optical mirror and the atom mirror is that ... to reflect photons one only needs a suitable metallic surface, [but] to reflect atoms one needs to create some sort of repulsive force for the atoms as they near the surface."
The Cal Tech research team "fabricated a magnetic mirror by etching a common hard drive, and used this mirror to reflect a cold cloud of cesium atoms," wrote lead researcher Hideo Mabuchi.
The common hard drive, Mabuchi explained, has several features that make it the perfect raw material for atomic mirror makers -- a large, flat, magnetic surface; smooth contours; and rigid construction.
Using the same photolithography techniques standard in the semiconductor industry, Mabuchi and his team etched the hard drive with photoresist.
"We simply ripped the hard drive out of an old computer lying around the lab," Lev said. "To make an atom mirror out of it, we had to etch trenches into the surface to effectively create long strips of parallel bar magnets that are one micron wide and spaced by two microns."
Follow the Bouncing Atoms
Once magnetized, the mirror repels -- or in this case, reflects -- incoming atoms.
"If a cloud of cold atoms is dropped on the atom mirror, they will bounce up and down in much the same manner as a rubber ball falling on the floor," Lev told NewsFactor.
The atomic mirror also directs atoms the same way an optical mirror directs beams of light.
"A light beam aimed a 45 degrees to the surface of an optical mirror reflects at 90 degrees from the incoming beam," Lev explained. "If one were to do the same with a beam of cold atoms impinging at 45 degrees, then the beam of atoms would also reflect from the atom mirror at 90 degrees from the incoming beam."
From Optic to Atomic
Atomic mirror makers see reflections of the past in futuristic atomic optics. "Atom optics is the subject of manipulating cold atoms using mirrors, lenses, wave guides and traps, much as photons are controlled using the traditional tools of optics," said University of Sussex physics professor E.A. Hinds, who pioneered the creation of magnetic atom mirrors.
"Hinds' group at Sussex used a floppy drive a few years ago," Lev explained. "Our hard drive mirror has some advantages over the floppy-drive mirror."
Atomic optics may find application in another burgeoning tech field that remains in early infancy -- quantum-computer science.
"One exciting prospect is to use the atom mirror, combined with electric fields, to perform quantum Latest News about quantum logic gates necessary for building a quantum computer," said Lev.