Washington: University of Texas researchers have developed a twin-technique to control atoms, marking a major step forward in atomic physics with a variety of scientific and technological applications.

The technique can also be used to determine the mass of the neutrino, the primary candidate for dark matter. The method, developed by Mark Raizen and his team, stopped atoms by passing a supersonic beam through an "atomic coil-gun" and cooled them using "single-photon cooling".

The coil-gun works by shooting a supersonic beam of atoms through a three mm bore wrapped by 64 magnetic coils made of copper wire (thus, 64 stages). The coils slow the atoms by making them climb a "magnetic hill". The hill is removed before the atoms have time to roll off and regain speed, and the atoms become magnetically trapped.

"The wonderful thing about the coil-gun technology is its simplicity," said Raizen. "We use ordinary copper wire for the coils. The hope is that this will allow others to use the technique to trap and cool the other elements." Key to the success of the coil-gun is the use of supersonic beam technology developed by Raizen's collaborator, Uzi Even, from Tel Aviv University.

"Our methods open up whole new avenues of research," said Raizen, a physicist. "We can control almost any atom and many molecules," reports sciencedaily. The results, published in two papers in the March 7 issue of Physical Review Letters, are the culmination of years of work trapping and cooling atoms by Raizen and his research group. Previously atoms have been cooled to a point near absolute zero (minus 273 degrees Celsius) using laser cooling, a method recognised by the Nobel Prize in Physics in 1997.

Despite its enormous success, laser cooling has been limited to a small set of atoms in the periodic table. Raizen said his method could be used in tandem to trap and cool near absolute zero any of the paramagnetic atoms, which make up over 85 per cent of the periodic table.

Source : IANS